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Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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1

Imaging and sensing based on muon tomography  

DOE Patents (OSTI)

Techniques, apparatus and systems for detecting particles such as muons for imaging applications. Subtraction techniques are described to enhance the processing of the muon tomography data.

Morris, Christopher L; Saunders, Alexander; Sossong, Michael James; Schultz, Larry Joe; Green, J. Andrew; Borozdin, Konstantin N; Hengartner, Nicolas W; Smith, Richard A; Colthart, James M; Klugh, David C; Scoggins, Gary E; Vineyard, David C

2012-10-16T23:59:59.000Z

2

Our Next Two Steps for Fukushima Daiichi Muon Tomography  

SciTech Connect

After the vast disasters caused by the great earthquake and tsunami in eastern Japan, we proposed applying our Muon Tomography (MT) technique to help and improve the emergency situation at Fukushima Daiichi using cosmic-ray muons. A reactor-tomography team was formed at LANL which was supported by the Laboratory as a response to a request by the former Japanese Prime Minister, Naoto Kan. Our goal is to help the Japanese people and support remediation of the reactors. At LANL, we have carried out a proof-of-principle technical demonstration and simulation studies that established the feasibility of MT to image a reactor core. This proposal covers the next two critical steps for Fukushima Daiichi Muon Imaging: (1) undertake case study mock-up experiments of Fukushima Daiichi, and (2) system optimization. We requested funding to the US and Japanese government to assess damage of reactors at Fukushima Daiichi. The two steps will bring our project to the 'ready-to-go' level.

Miyadera, Haruo [Los Alamos National Laboratory

2012-04-11T23:59:59.000Z

3

COSMIC-RAY MUON TOMOGRAPHY AND ITS APPLICATION TO THE DETECTION OF HIGH-Z MATERIALS  

E-Print Network (OSTI)

. The mean energy of the muons at the ground is about 4 GeV. The integral 1 #12;intensity of vertical muons change their directions due to the multiple scattering, lose their energy and finally get stopped. A muonCOSMIC-RAY MUON TOMOGRAPHY AND ITS APPLICATION TO THE DETECTION OF HIGH-Z MATERIALS Konstantin

Kurien, Susan

4

Nuclear Waste Imaging and Spent Fuel Verification by Muon Tomography  

E-Print Network (OSTI)

This paper explores the use of cosmic ray muons to image the contents of shielded containers and detect high-Z special nuclear materials inside them. Cosmic ray muons are a naturally occurring form of radiation, are highly penetrating and exhibit large scattering angles on high Z materials. Specifically, we investigated how radiographic and tomographic techniques can be effective for non-invasive nuclear waste characterization and for nuclear material accountancy of spent fuel inside dry storage containers. We show that the tracking of individual muons, as they enter and exit a structure, can potentially improve the accuracy and availability of data on nuclear waste and the contents of Dry Storage Containers (DSC) used for spent fuel storage at CANDU plants. This could be achieved in near real time, with the potential for unattended and remotely monitored operations. We show that the expected sensitivity, in the case of the DSC, exceeds the IAEA detection target for nuclear material accountancy.

Jonkmans, G; Jewett, C; Thompson, M

2012-01-01T23:59:59.000Z

5

Characterising encapsulated nuclear waste using cosmic-ray muon tomography  

E-Print Network (OSTI)

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the UK Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

Anthony Clarkson; David J. Hamilton; Matthias Hoek; David G. Ireland; John R. Johnstone; Ralf Kaiser; Tibor Keri; Scott Lumsden; David F. Mahon; Bryan McKinnon; Morgan Murray; Siân Nutbeam-Tuffs; Craig Shearer; Guangliang Yang; Colin Zimmerman

2014-10-27T23:59:59.000Z

6

Characterising encapsulated nuclear waste using cosmic-ray muon tomography  

E-Print Network (OSTI)

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the UK Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

Clarkson, Anthony; Hoek, Matthias; Ireland, David G; Johnstone, John R; Kaiser, Ralf; Keri, Tibor; Lumsden, Scott; Mahon, David F; McKinnon, Bryan; Murray, Morgan; Nutbeam-Tuffs, Siân; Shearer, Craig; Yang, Guangliang; Zimmerman, Colin

2014-01-01T23:59:59.000Z

7

Neutron Tomography and Space  

E-Print Network (OSTI)

Kevin Shields, “Optimization of neutron tomography for rapidNEUTRON TOMOGRAPHY AND SPACE Hal Egbert, Ronald Walker, R.industrial applications[1]. Neutron Computed Tomography was

Egbert, Hal; Walker, Ronald; Flocchini, R.

2007-01-01T23:59:59.000Z

8

Atom Probe Tomography | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

Atom Probe Tomography Atom Probe Tomography The LEAP 4000 XHR local electrode atom probe tomography instrument enabled the first-ever comprehensive and accurate 3-D chemical...

9

Pseudolocal tomography  

DOE Patents (OSTI)

Local tomographic data is used to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. The relative attenuation data is input to a pseudo-local tomography function, where the difference between the internal density and the pseudo-local tomography function is computed across the discontinuity. The pseudo-local tomography function outputs the location of the discontinuity and the difference in density between the first density and the second density. 7 figs.

Katsevich, A.J.; Ramm, A.G.

1996-07-23T23:59:59.000Z

10

Pseudolocal tomography  

DOE Patents (OSTI)

Local tomographic data is used to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. The relative attenuation data is input to a pseudo-local tomography function, where the difference between the internal density and the pseudo-local tomography function is computed across the discontinuity. The pseudo-local tomography function outputs the location of the discontinuity and the difference in density between the first density and the second density.

Katsevich, Alexander J. (Los Alamos, NM); Ramm, Alexander G. (Manhattan, KS)

1996-01-01T23:59:59.000Z

11

Doppler Tomography  

E-Print Network (OSTI)

I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the inversion. Following this I discuss the issue of noise in Doppler images and possible methods for coping with it. Then I move on to look at the results of Doppler Tomography applied to cataclysmic variable stars. Outstanding successes to date are the discovery of two-arm spiral shocks in cataclysmic variable accretion discs and the probing of the stream/magnetospheric interaction in magnetic cataclysmic variable stars. Doppler tomography has also told us much about the stream/disc interaction in non-magnetic systems and the irradiation of the secondary star in all systems. The latter indirectly reveals such effects as shadowing by the accretion disc or stream. I discuss all of these and finish with some musings on possible future directions for the method. At the end I include a tabulation of Doppler maps published in refereed journals.

T. R. Marsh

2000-11-01T23:59:59.000Z

12

The Design and Performance of a Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers  

E-Print Network (OSTI)

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons are increasingly being exploited for the non-destructive assay of shielded containers in a wide range of applications. One such application is the characterisation of legacy nuclear waste materials stored within industrial containers. The design, assembly and performance of a prototype muon tomography system developed for this purpose are detailed in this work. This muon tracker comprises four detection modules, each containing orthogonal layers of Saint-Gobain BCF-10 2mm-pitch plastic scintillating fibres. Identification of the two struck fibres per module allows the reconstruction of the incoming and Coulomb-scattered muon trajectories. These allow the container content, with respect to the atomic number Z of the scattering material, to be determined through reconstruction of the scattering location and magnitude. On each detection layer, the light emitted by the fibre is detected by a single Hamamatsu H8500 MAPMT with two fibre...

Clarkson, Anthony; Hoek, Matthias; Ireland, David G; Johnstone, Russell; Kaiser, Ralf; Keri, Tibor; Lumsden, Scott; Mahon, David F; McKinnon, Bryan; Murray, Morgan; Nutbeam-Tuffs, Sian; Shearer, Craig; Staines, Cassie; Yang, Guangliang; Zimmerman, Colin

2013-01-01T23:59:59.000Z

13

GEANT4 Simulation of a Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers  

E-Print Network (OSTI)

Cosmic-ray muons are highly penetrative charged particles that are observed at sea level with a flux of approximately one per square centimetre per minute. They interact with matter primarily through Coulomb scattering, which is exploited in the field of muon tomography to image shielded objects in a wide range of applications. In this paper, simulation studies are presented that assess the feasibility of a scintillating-fibre tracker system for use in the identification and characterisation of nuclear materials stored within industrial legacy waste containers. A system consisting of a pair of tracking modules above and a pair below the volume to be assayed is simulated within the GEANT4 framework using a range of potential fibre pitches and module separations. Each module comprises two orthogonal planes of fibres that allow the reconstruction of the initial and Coulomb-scattered muon trajectories. A likelihood-based image reconstruction algorithm has been developed that allows the container content to be det...

Clarkson, Anthony; Hoek, Matthias; Ireland, David G; Johnstone, Russell; Kaiser, Ralf; Keri, Tibor; Lumsden, Scott; Mahon, David F; McKinnon, Bryan; Murray, Morgan; Nutbeam-Tuffs, Sian; Shearer, Craig; Staines, Cassie; Yang, Guangliang; Zimmerman, Colin

2013-01-01T23:59:59.000Z

14

Turbocharging Quantum Tomography.  

SciTech Connect

Quantum tomography is used to characterize quantum operations implemented in quantum information processing (QIP) hardware. Traditionally, state tomography has been used to characterize the quantum state prepared in an initialization procedure, while quantum process tomography is used to characterize dynamical operations on a QIP system. As such, tomography is critical to the development of QIP hardware (since it is necessary both for debugging and validating as-built devices, and its results are used to influence the next generation of devices). But tomography su %7C ers from several critical drawbacks. In this report, we present new research that resolves several of these flaws. We describe a new form of tomography called gate set tomography (GST), which unifies state and process tomography, avoids prior methods critical reliance on precalibrated operations that are not generally available, and can achieve unprecedented accuracies. We report on theory and experimental development of adaptive tomography protocols that achieve far higher fidelity in state reconstruction than non-adaptive methods. Finally, we present a new theoretical and experimental analysis of process tomography on multispin systems, and demonstrate how to more e %7C ectively detect and characterize quantum noise using carefully tailored ensembles of input states.

Blume-Kohout, Robin J; Gamble, John King,; Nielsen, Erik; Maunz, Peter Lukas Wilhelm; Scholten, Travis L.; Rudinger, Kenneth Michael

2015-01-01T23:59:59.000Z

15

Modulated Luminescent Tomography  

E-Print Network (OSTI)

Two such techniques, X-ray luminescence computed tomography (XLCT), [9] and X-ray micro- ..... Optical-Thermal Response of Laser-Irradiated Tissue.

2014-09-10T23:59:59.000Z

16

GEANT4 Simulation of a Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers  

E-Print Network (OSTI)

Cosmic-ray muons are highly penetrative charged particles that are observed at sea level with a flux of approximately one per square centimetre per minute. They interact with matter primarily through Coulomb scattering, which is exploited in the field of muon tomography to image shielded objects in a wide range of applications. In this paper, simulation studies are presented that assess the feasibility of a scintillating-fibre tracker system for use in the identification and characterisation of nuclear materials stored within industrial legacy waste containers. A system consisting of a pair of tracking modules above and a pair below the volume to be assayed is simulated within the GEANT4 framework using a range of potential fibre pitches and module separations. Each module comprises two orthogonal planes of fibres that allow the reconstruction of the initial and Coulomb-scattered muon trajectories. A likelihood-based image reconstruction algorithm has been developed that allows the container content to be determined with respect to the atomic number Z of the scattering material. Images reconstructed from this simulation are presented for a range of anticipated scenarios that highlight the expected image resolution and the potential of this system for the identification of high-Z materials within a shielded, concrete-filled container. First results from a constructed prototype system are presented in comparison with those from a detailed simulation. Excellent agreement between experimental data and simulation is observed showing clear discrimination between the different materials assayed throughout.

Anthony Clarkson; David J. Hamilton; Matthias Hoek; David G. Ireland; Russell Johnstone; Ralf Kaiser; Tibor Keri; Scott Lumsden; David F. Mahon; Bryan McKinnon; Morgan Murray; Sian Nutbeam-Tuffs; Craig Shearer; Cassie Staines; Guangliang Yang; Colin Zimmerman

2013-09-13T23:59:59.000Z

17

Tomography and reliable information  

Science Journals Connector (OSTI)

Principles of tomography are developed and applied to the problem of two-view interferometry on a tokamak plasma. It is shown that M equispaced views, or projections, of a...

Howard, John

1988-01-01T23:59:59.000Z

18

Multi-Scale Optical Coherence Tomography Imaging  

E-Print Network (OSTI)

Fourier domain optical coherence tomography and methods forspeed spectral-domain optical coherence tomography at 1.3umJ. G. (1991). Optical coherence tomography. Science, 254(

Oliveira, Michael

2014-01-01T23:59:59.000Z

19

Geometric Tomography: A Limited-View Approach for Computed Tomography  

E-Print Network (OSTI)

Geometric Tomography: A Limited-View Approach for Computed Tomography Peter B. Noël, Jinhui Xu Keywords Computed Tomography; Geometric Compressed Sensing; Topo- logical Peeling. ABSTRACT Computed to generate 3D data, denoted f, directly from projec- tions, denoted g. Thus, the projection relationship can

Corso, Jason J.

20

Waste inspection tomography (WIT)  

SciTech Connect

The WIT program will provide an inspection system that offers the nuclear waste evaluator a unique combination of tools for regulatory-driven characterization of low-level waste (LLW), transuranic waste (TRU), and mixed waste drums. WIT provides nondestructive, noninvasive, and environmentally safe inspections using X-ray and gamma ray technologies, with reasonable cost and throughput. Two emission imaging techniques will be employed for characterizing materials in waste containers. The first of these is gamma emission tomography, commonly called single-photon emission computed tomography (SPECT). Rather than using an external radiation source, SPECT uses the emission of radioactive materials within the object of interest for imaging. In this case, emission from actual nuclear waste within a container will provide a three-dimensional image of the radioactive substances in the container. The second emission technique will use high-purity germanium detectors for gamma ray spectroscopy. This technique, called nondestructive assay (NDA), can identify the emitting isotopic species and strength. Work in emission tomography and assay of nuclear waste has been undertaken at Lawrence Livermore National Laboratory using a technique called Passive Tomography. Results from a process development unit are presented.

Bernardi, R.T.; Han, K.S.

1994-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Neutron computed tomography  

E-Print Network (OSTI)

to make the Donner Algorithms run. TABLE OF CONTEliiTS CHAPTF. . R I NEI. TRON RADIOGRAPHY . I. 1 Background . I. 2 Theory . l. 3 Neutron Beam Characterization I. 4 Image Detectors . COMPI'TED TOMOGRAPHY . Il I Background . II. 2 Notation II. 3... data which is generated by rays traveling (and being attenuated) in straight lines. However in neutron radiography, what is measured is, to most extents, the levels of neutrons which are not attenuated. Neutrons are particles. They scatter...

Russell, Clifford Marlow

2012-06-07T23:59:59.000Z

22

Computed Tomography Status  

DOE R&D Accomplishments (OSTI)

Computed tomography (CT) is a relatively new radiographic technique which has become widely used in the medical field, where it is better known as computerized axial tomographic (CAT) scanning. This technique is also being adopted by the industrial radiographic community, although the greater range of densities, variation in samples sizes, plus possible requirement for finer resolution make it difficult to duplicate the excellent results that the medical scanners have achieved.

Hansche, B. D.

1983-00-00T23:59:59.000Z

23

Enhanced local tomography  

DOE Patents (OSTI)

Local tomography is enhanced to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. In a first method for evaluating the value of the discontinuity, the relative attenuation data is inputted to a local tomography function .function..sub..LAMBDA. to define the location S of the density discontinuity. The asymptotic behavior of .function..sub..LAMBDA. is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA.. In a second method for evaluating the value of the discontinuity, a gradient value for a mollified local tomography function .gradient..function..sub..LAMBDA..epsilon. (x.sub.ij) is determined along the discontinuity; and the value of the jump of the density across the discontinuity curve (or surface) S is estimated from the gradient values.

Katsevich, Alexander J. (Los Alamos, NM); Ramm, Alexander G. (Manhattan, KS)

1996-01-01T23:59:59.000Z

24

Generalized local emission tomography  

DOE Patents (OSTI)

Emission tomography enables locations and values of internal isotope density distributions to be determined from radiation emitted from the whole object. In the method for locating the values of discontinuities, the intensities of radiation emitted from either the whole object or a region of the object containing the discontinuities are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the isotope density discontinuity. The asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) knowing pointwise values of the attenuation coefficient within the object. In the method for determining the location of the discontinuity, the intensities of radiation emitted from an object are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the density discontinuity and the location .GAMMA. of the attenuation coefficient discontinuity. Pointwise values of the attenuation coefficient within the object need not be known in this case.

Katsevich, Alexander J. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

25

Positron Emission Tomography (PET)  

DOE R&D Accomplishments (OSTI)

Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

Welch, M. J.

1990-01-00T23:59:59.000Z

26

Radial reflection diffraction tomography  

DOE Patents (OSTI)

A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a "pitch/catch" operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes.

Lehman, Sean K.

2012-12-18T23:59:59.000Z

27

High energy neutron Computed Tomography developed  

NLE Websites -- All DOE Office Websites (Extended Search)

objects. May 9, 2014 Neutron tomography horizontal "slice" of a tungsten and polyethylene test object containing tungsten carbide BBs. Neutron tomography horizontal "slice"...

28

Electrical Impedance Tomography Liliana Borcea  

E-Print Network (OSTI)

Electrical Impedance Tomography Liliana Borcea #3; September 3, 2002 Abstract We review theoretical and numerical studies of the inverse problem of electrical impedance tomography which seeks the electrical conductivity and permittivity inside a body, given simul- taneous measurements of electrical currents

Borcea, Liliana

29

Waste Inspection Tomography (WIT)  

SciTech Connect

Waste Inspection Tomography (WIT) provides mobile semi-trailer mounted nondestructive examination (NDE) and assay (NDA) for nuclear waste drum characterization. WIT uses various computed tomography (CT) methods for both NDE and NDA of nuclear waste drums. Low level waste (LLW), transuranic (TRU), and mixed radioactive waste can be inspected and characterized without opening the drums. With externally transmitted x-ray NDE techniques, WIT has the ability to identify high density waste materials like heavy metals, define drum contents in two- and three-dimensional space, quantify free liquid volumes through density and x-ray attenuation coefficient discrimination, and measure drum wall thickness. With waste emitting gamma-ray NDA techniques, WIT can locate gamma emitting radioactive sources in two- and three-dimensional space, identify gamma emitting isotopic species, identify the external activity levels of emitting gamma-ray sources, correct for waste matrix attenuation, provide internal activity approximations, and provide the data needed for waste classification as LLW or TRU. The mobile feature of WIT allows inspection technologies to be brought to the nuclear waste drum storage site without the need to relocate drums for safe, rapid, and cost-effective characterization of regulated nuclear waste. The combination of these WIT characterization modalities provides the inspector with an unprecedented ability to non-invasively characterize the regulated contents of waste drums as large as 110 gallons, weighing up to 1,600 pounds. Any objects that fit within these size and weight restrictions can also be inspected on WIT, such as smaller waste bags and drums that are five and thirty-five gallons.

Bernardi, R.T.

1995-12-01T23:59:59.000Z

30

Teleseismic transmission and reflection tomography  

E-Print Network (OSTI)

The aim of seismic tomography is to determine a model of Earth properties that best explain observed seismic data. In practice, the limitations placed on our observations and computational capabilities force us to make a ...

Burdick, Scott A. (Scott Anthony)

2014-01-01T23:59:59.000Z

31

Resistivity Tomography | Open Energy Information  

Open Energy Info (EERE)

Resistivity Tomography Resistivity Tomography Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Resistivity Tomography Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Resistivity Log Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Cost Information Low-End Estimate (USD): 60.986,098 centUSD 0.061 kUSD 6.098e-5 MUSD 6.098e-8 TUSD / foot Median Estimate (USD): 76.227,622 centUSD 0.0762 kUSD 7.622e-5 MUSD 7.622e-8 TUSD / foot High-End Estimate (USD): 106.7110,671 centUSD 0.107 kUSD 1.0671e-4 MUSD 1.0671e-7 TUSD / foot Time Required Low-End Estimate: 1 days0.00274 years

32

TE Connectivity Finds Answers in Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

TE Connectivity Finds Answers in Tomography TE Connectivity Finds Answers in Tomography Print Thursday, 22 August 2013 10:50 TE Connectivity is a world leader in connectivity-the...

33

Self-Guided Quantum Tomography  

Science Journals Connector (OSTI)

We introduce a self-learning tomographic technique in which the experiment guides itself to an estimate of its own state. Self-guided quantum tomography uses measurements to directly test hypotheses in an iterative algorithm which converges to the true state. We demonstrate through simulation on many qubits that Self-guided quantum tomography is a more efficient and robust alternative to the usual paradigm of taking a large amount of informationally complete data and solving the inverse problem of postprocessed state estimation.

Christopher Ferrie

2014-11-07T23:59:59.000Z

34

Discrete Tomography: A Neural Network Approach  

E-Print Network (OSTI)

Abstract Tomography tries to reconstruct an object from a number of projections in multiple directions quality reconstructions from a limited set of projections, while avoiding image artifacts that are often present in traditional approaches. 1 Introduction Tomography, or more especially computed tomography

Kosters, Walter

35

Computed tomography:the details.  

SciTech Connect

Computed Tomography (CT) is a well established technique, particularly in medical imaging, but also applied in Synthetic Aperture Radar (SAR) imaging. Basic CT imaging via back-projection is treated in many texts, but often with insufficient detail to appreciate subtleties such as the role of non-uniform sampling densities. Herein are given some details often neglected in many texts.

Doerry, Armin Walter

2007-07-01T23:59:59.000Z

36

Measuring momentum for charged particle tomography  

DOE Patents (OSTI)

Methods, apparatus and systems for detecting charged particles and obtaining tomography of a volume by measuring charged particles including measuring the momentum of a charged particle passing through a charged particle detector. Sets of position sensitive detectors measure scattering of the charged particle. The position sensitive detectors having sufficient mass to cause the charged particle passing through the position sensitive detectors to scatter in the position sensitive detectors. A controller can be adapted and arranged to receive scattering measurements of the charged particle from the charged particle detector, determine at least one trajectory of the charged particle from the measured scattering; and determine at least one momentum measurement of the charged particle from the at least one trajectory. The charged particle can be a cosmic ray-produced charged particle, such as a cosmic ray-produced muon. The position sensitive detectors can be drift cells, such as gas-filled drift tubes.

Morris, Christopher (Los Alamos, NM); Fraser, Andrew Mcleod (Los Alamos, NM); Schultz, Larry Joe (Los Alamos, NM); Borozdin, Konstantin N. (Los Alamos, NM); Klimenko, Alexei Vasilievich (Maynard, MA); Sossong, Michael James (Los Alamos, NM); Blanpied, Gary (Lexington, SC)

2010-11-23T23:59:59.000Z

37

Software-defined Radio based Wireless Tomography: Experimental Demonstration and  

E-Print Network (OSTI)

1 Software-defined Radio based Wireless Tomography: Experimental Demonstration and Verification presents an experimental demonstration of Software-Defined Radio (SDR) based wireless tomography us- ing follows our vision and previous theoretical study of wireless tomography which combines wireless

Qiu, Robert Caiming

38

Phenotyping transgenic embryonic murine hearts using optical coherence tomography  

E-Print Network (OSTI)

Phenotyping transgenic embryonic murine hearts using optical coherence tomography Michael W optical coherence tomography (OCT) to characterize the morphological phenotype of embryonic murine hearts the etiology of heart defects. Optical coherence tomography (OCT)6,7 measures coherently gated backreflected

39

Properties of Some Integral Transforms Arising in Tomography  

E-Print Network (OSTI)

This dissertation deals with several types of imaging: radio tomography, single scattering optical tomography, photoacoustic tomography, and Compton camera imaging. Each of these tomographic techniques leads to a Radon-type transform...

Moon, Sunghwan

2013-10-11T23:59:59.000Z

40

Computed Tomography software and standards  

SciTech Connect

This document establishes the software design, nomenclature, and conventions for industrial Computed Tomography (CT) used in the Nondestructive Evaluation Section at Lawrence Livermore National Laboratory. It is mainly a users guide to the technical use of the CT computer codes, but also presents a proposed standard for describing CT experiments and reconstructions. Each part of this document specifies different aspects of the CT software organization. A set of tables at the end describes the CT parameters of interest in our project. 4 refs., 6 figs., 1 tab.

Azevedo, S.G.; Martz, H.E.; Skeate, M.F.; Schneberk, D.J.; Roberson, G.P.

1990-02-20T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Contribution of atom-probe tomography to a better understanding...  

NLE Websites -- All DOE Office Websites (Extended Search)

atom-probe tomography to a better understanding of glass alteration mechanisms: application to a nuclear glass Contribution of atom-probe tomography to a better understanding of...

42

Resistivity Tomography At Crump's Hot Springs Area (DOE GTP)...  

Open Energy Info (EERE)

Tomography At Crump's Hot Springs Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Resistivity Tomography At Crump's Hot Springs...

43

Understanding Atom Probe Tomography of Oxide-Supported Metal...  

NLE Websites -- All DOE Office Websites (Extended Search)

Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Understanding Atom Probe Tomography of Oxide-Supported Metal...

44

Using X-Ray Computed Tomography in Pore Structure Characterization...  

NLE Websites -- All DOE Office Websites (Extended Search)

Using X-Ray Computed Tomography in Pore Structure Characterization for a Berea Sandstone: Resolution Effect. Using X-Ray Computed Tomography in Pore Structure Characterization for...

45

ALGEBRAIC ASPECTS OF EMISSION TOMOGRAPHY WITH ABSORPTION  

E-Print Network (OSTI)

ALGEBRAIC ASPECTS OF EMISSION TOMOGRAPHY WITH ABSORPTION L. Hajdu and R. Tijdeman Abstract of emission tomography with absorption, con- sider a ray (such as light or X-ray) transmitting through #1; e #22;x ; where #22; #21; 0 denotes the absorption coeÃ?cient of the material, and x is the length

Tijdeman, Robert

46

Fast Globally Convergent Reconstruction in Emission Tomography  

E-Print Network (OSTI)

considerable speedup by using only a subset of the projection data per sub- iteration. However, OSEM1 Fast Globally Convergent Reconstruction in Emission Tomography Using COSEM, an Incremental EM globally convergent incremental EM algorithms for reconstruction in emission tomography, COSEM- ML

Rangarajan, Anand

47

Improving Electrical Resistivity Tomography for Characterization of  

E-Print Network (OSTI)

Improving Electrical Resistivity Tomography for Characterization of Non-point Source Contaminants runoff on Arizona's potable water. Electrical resistivity tomography (ERT) shows promise as a noninvasive on the environment. Urban and agricultural runoff are often associated with an increase in water electrical

Fay, Noah

48

Lorentz Force Electrical Impedance Tomography  

E-Print Network (OSTI)

This article describes a method called Lorentz Force Electrical Impedance Tomography. The electrical conductivity of biological tissues can be measured through their sonication in a magnetic field: the vibration of the tissues inside the field induces an electrical current by Lorentz force. This current, detected by electrodes placed around the sample, is proportional to the ultrasonic pressure, to the strength of the magnetic field and to the electrical conductivity gradient along the acoustic axis. By focusing at different places inside the sample, a map of the electrical conductivity gradient can be established. In this study experiments were conducted on a gelatin phantom and on a beef sample, successively placed in a 300 mT magnetic field and sonicated with an ultrasonic transducer focused at 21 cm emitting 500 kHz bursts. Although all interfaces are not visible, in this exploratory study a good correlation is observed between the electrical conductivity image and the ultrasonic image. This method offers...

Grasland-Mongrain, Pol; Chapelon, Jean-Yves; Lafon, Cyril

2014-01-01T23:59:59.000Z

49

Positron emission tomography wrist detector  

DOE Patents (OSTI)

A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal representing a time-of-occurrence of an annihilation event, generating an address signal representing a channel detecting the annihilation event, and generating a channel signal including the time and address signals. The method also includes generating a composite signal including the channel signal and another similarly generated channel signal concerning another annihilation event. An apparatus that serially transfers annihilation information includes a time signal generator, address signal generator, channel signal generator, and composite signal generator. The time signal is asynchronous and the address signal is synchronous to a clock signal. A PET scanner includes a scintillation array, detection array, front-end array, and a serial encoder. The serial encoders include the time signal generator, address signal generator, channel signal generator, and composite signal generator.

Schlyer, David J. (Bellport, NY); O'Connor, Paul (Bellport, NY); Woody, Craig (Setauket, NY); Junnarkar, Sachin Shrirang (Sound Beach, NY); Radeka, Veljko (Bellport, NY); Vaska, Paul (Sound Beach, NY); Pratte, Jean-Francois (Stony Brook, NY)

2006-08-15T23:59:59.000Z

50

Collimator-free photon tomography  

DOE Patents (OSTI)

A method of uncollimated single photon emission computed tomography includes administering a radioisotope to a patient for producing gamma ray photons from a source inside the patient. Emissivity of the photons is measured externally of the patient with an uncollimated gamma camera at a plurality of measurement positions surrounding the patient for obtaining corresponding energy spectrums thereat. Photon emissivity at the plurality of measurement positions is predicted using an initial prediction of an image of the source. The predicted and measured photon emissivities are compared to obtain differences therebetween. Prediction and comparison is iterated by updating the image prediction until the differences are below a threshold for obtaining a final prediction of the source image. 6 figs.

Dilmanian, F.A.; Barbour, R.L.

1998-10-06T23:59:59.000Z

51

Collimator-free photon tomography  

DOE Patents (OSTI)

A method of uncollimated single photon emission computed tomography includes administering a radioisotope to a patient for producing gamma ray photons from a source inside the patient. Emissivity of the photons is measured externally of the patient with an uncollimated gamma camera at a plurality of measurement positions surrounding the patient for obtaining corresponding energy spectrums thereat. Photon emissivity at the plurality of measurement positions is predicted using an initial prediction of an image of the source. The predicted and measured photon emissivities are compared to obtain differences therebetween. Prediction and comparison is iterated by updating the image prediction until the differences are below a threshold for obtaining a final prediction of the source image.

Dilmanian, F. Avraham (Yaphank, NY); Barbour, Randall L. (Westbury, NY)

1998-10-06T23:59:59.000Z

52

Axial Tomography from Digitized Real Time Radiography  

DOE R&D Accomplishments (OSTI)

Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

Zolnay, A. S.; McDonald, W. M.; Doupont, P. A.; McKinney, R. L.; Lee, M. M.

1985-01-18T23:59:59.000Z

53

Practical Characterization of Quantum Devices without Tomography  

Science Journals Connector (OSTI)

Quantum tomography is the main method used to assess the quality of quantum information processing devices. However, the amount of resources needed for quantum tomography is exponential in the device size. Part of the problem is that tomography generates much more information than is usually sought. Taking a more targeted approach, we develop schemes that enable (i) estimating the fidelity of an experiment to a theoretical ideal description, (ii) learning which description within a reduced subset best matches the experimental data. Both these approaches yield a significant reduction in resources compared to tomography. In particular, we demonstrate that fidelity can be estimated from a number of simple experiments that is independent of the system size, removing an important roadblock for the experimental study of larger quantum information processing units.

Marcus P. da Silva; Olivier Landon-Cardinal; David Poulin

2011-11-16T23:59:59.000Z

54

Phase-Conjugate Optical Coherence Tomography  

E-Print Network (OSTI)

We demonstrate a new type of optical coherence tomography using only classical resources to achieve results that are typically associated with quantum-enhanced metrology: factor-of-two axial resolution enhancement and ...

Shapiro, Jeffrey H.

55

Positron Emission Tomography Physics, Instrumentation, Data Analysis  

E-Print Network (OSTI)

1 Positron Emission Tomography Physics, Instrumentation, Data Analysis Carl K. Hoh, MD Department fast computer Filtered Back Projection Iterative Reconstruction PET Image Reconstruction #12 PET Scanner Design · Smaller individual crystal size = better spatial resolution · Physical limit

Liu, Thomas T.

56

3D Imaging with Holographic Tomography  

Science Journals Connector (OSTI)

There are two main types of tomography that enable the 3D internal structures of objects to be reconstructed from scattered data. The commonly known computerized tomography (CT) give good results in the x?ray wavelength range where the filtered back?projection theorem and Radon transform can be used. These techniques rely on the Fourier projection?slice theorem where rays are considered to propagate straight through the object. Another type of tomography called ‘diffraction tomography’ applies in applications in optics and acoustics where diffraction and scattering effects must be taken into account. The latter proves to be a more difficult problem as light no longer travels straight through the sample. Holographic tomography is a popular way of performing diffraction tomography and there has been active experimental research on reconstructing complex refractive index data using this approach recently. However there are two distinct ways of doing tomography: either by rotation of the object or by rotation of the illumination while fixing the detector. The difference between these two setups is intuitive but needs to be quantified. From Fourier optics and information transformation point of view we use 3D transfer function analysis to quantitatively describe how spatial frequencies of the object are mapped to the Fourier domain. We first employ a paraxial treatment by calculating the Fourier transform of the defocused OTF. The shape of the calculated 3D CTF for tomography by scanning the illumination in one direction only takes on a form that we might call a ’peanut ’ compared to the case of object rotation where a diablo is formed the peanut exhibiting significant differences and non?isotropy. In particular there is a line singularity along one transverse direction. Under high numerical aperture conditions the paraxial treatment is not accurate and so we make use of 3D analytical geometry to calculate the behaviour in the non?paraxial case. This time we obtain a similar peanut but without the line singularity.

Colin J. R. Sheppard; Shan Shan Kou

2010-01-01T23:59:59.000Z

57

High-resolution imaging of microvasculature in human skin in-vivo with optical coherence tomography  

E-Print Network (OSTI)

using swept-source optical coherence tomography,” Opt. Lett.J. G. Fujimoto, “Optical coherence tomography,” Science 254(volumes using optical coherence tomography,” Opt. Lett. 22(

Liu, Gangjun; Jia, Wangcun; Sun, Victor; Choi, Bernard; Chen, Zhongping

2012-01-01T23:59:59.000Z

58

Reference spectrum extraction and fixed-pattern noise removal in optical coherence tomography  

E-Print Network (OSTI)

OCIS codes: (110.4500) Optical coherence tomography; (170.4500) Optical coherence tomography; (100.2000) Digitalvs. time domain optical coherence tomography,” Opt. Express

Moon, Sucbei; Lee, Sang-Won; Chen, Zhongping

2010-01-01T23:59:59.000Z

59

In vivo three-dimensional microelectromechanical endoscopic swept source optical coherence tomography  

E-Print Network (OSTI)

with endoscopic optical coherence tomography”, Opt. Express,G. Fujimoto, "Optical coherence tomography," Science, 254,endoscope for optical coherence tomography”,Opt. Lett. 21,

Su, Jianping; Zhang, Jun; Yu, Linfeng; Chen, Zhongping

2007-01-01T23:59:59.000Z

60

Economical standard quantum process tomography  

E-Print Network (OSTI)

Recently, Bendersky \\emph{et al.} developed a method to complete the task of characterizing an arbitrary $\\chi$ matrix element in a scalable way, Phys. Rev. Lett. Vol. \\textbf{100}, 190403(2008), where an auxiliary system was needed. In present work, we shall show that the same task can also be completed within the scheme of standard quantum process tomography (SQPT) where there is no requirement for ancilla. Our method depends on two observations: With the elaborately chosen operators basis, the SQPT may have an economical form where a single run of experiment, in which we measure the expectation value of a chosen operator in the outport of the quantum channel with a known input, is sufficient to characterize a selected $\\chi$ matrix element; With the progress recently achieved in quantum entanglement detection, we also find that the number of the experimental settings to realize the experiment for the selected $\\chi$ matrix element does not exceed 2N for the N-qubits system. For practice, our scheme can be applied for the cases where the controlled two-body interaction is neither available nor desirable.

Xiaohua Wu; Ke Xu

2010-11-30T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Positron Emission Tomography (PET) and Positron Scanning  

Office of Scientific and Technical Information (OSTI)

DOE R&D Accomplishments DOE R&D Accomplishments Search All Database Web Pages for Go The Basics Home About What's New FAQ Contact Us Laureates Nobel Laureates Fermi Laureates Nobel Physicists Nobel Chemists Medicine Nobels Explore Insights SC Stories Snapshots R&D Nuggets Database Search Browse Reports Database Help Finding Aids Site Map A - Z Index Menu Synopsis Blog Archive QR Code RSS Archive Tag Cloud Videos Widget XML Bookmark and Share Positron Emission Tomography (PET) and Positron Scanning Resources with Additional Information Positron Emission Tomography (PET) Scanner Courtesy Lawrence Berkeley National Laboratory 'Positron Emission Tomography ... [is a medical imaging technique that] can track chemical reactions in living tissues and merges chemistry with biological imaging. Its strength has been in studies of the brain where there has been significant progress in investigations of drug addiction, aging, mental illness, and neurogenic disorders. Positron Emission Tomography (PET) had its genesis in hot-atom chemical research supported by the Chemical Sciences Division of the Office of Basic Energy Sciences. Through this research it was learned, over many years, how to prepare short-lived positron emitters such as 18F whose half-life is 110 minutes. In 1975, the molecule [18F]fluorodeoxyglucose was successfully synthesized at Brookhaven National Laboratory (BNL) and set the stage for Positron Emission Tomography of the human brain.'

62

TE Connectivity Finds Answers in Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

TE Connectivity Finds Answers in TE Connectivity Finds Answers in Tomography TE Connectivity Finds Answers in Tomography Print Thursday, 22 August 2013 10:50 TE Connectivity is a world leader in connectivity-the $13 billion global company designs and manufactures more than 500,000 different electronic connectivity products for the automotive, energy, industrial, broadband communications, consumer device, healthcare, aerospace, and defense industries. TE Connectivity has a long-standing commitment to innovation and engineering excellence. Their products help address challenges arising from companies' need for energy efficiency, always-on communications, and ever-increasing productivity. Recently, a team led by TE's senior manager of materials development, Dr. Jerzy Gazda (at left), has been investigating how ALS tomography capabilities can help the company develop more efficient connectors.

63

Multilevel bioluminescence tomography based on radiative transfer equation  

E-Print Network (OSTI)

, "A fast forward solver of radiative transfer equation," Transport Theory and Statistical Physics 38Multilevel bioluminescence tomography based on radiative transfer equation Part 1: l1 approach for bioluminescence tomography based on radiative transfer equation with the emphasis on improving

Soatto, Stefano

64

Positron Computed Tomography: Current State, Clinical Results and Future Trends  

DOE R&D Accomplishments (OSTI)

An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends. (ACR)

Schelbert, H. R.; Phelps, M. E.; Kuhl, D. E.

1980-09-00T23:59:59.000Z

65

Tomography and High-Resolution Electron Microscopy Study of Surfaces...  

NLE Websites -- All DOE Office Websites (Extended Search)

Tomography and High-Resolution Electron Microscopy Study of Surfaces and Porosity in a Plate-Like ?-Al2O3. Tomography and High-Resolution Electron Microscopy Study of...

66

Wavelength-dependent scattering in spectroscopic optical coherence tomography  

E-Print Network (OSTI)

Wavelength-dependent scattering in spectroscopic optical coherence tomography Chenyang Xu, P. Scott of light scattering spectroscopy (LSS) and the spatial localization of optical coherence tomography (OCT.4500) Optical coherence tomography; (290.0290) Scattering; (300.0300) Spectroscopy References and links 1. A

Bhargava, Rohit

67

Inverse scattering for rotationally scanned optical coherence tomography  

E-Print Network (OSTI)

Inverse scattering for rotationally scanned optical coherence tomography Daniel L. Marks, Tyler S May 16, 2006; posted May 26, 2006 (Doc. ID 67358) Optical coherence tomography of luminal structures coherence tomography1,2 (OCT), is determined in large part by the degree to which the images provide

Bhargava, Rohit

68

Cone Beam Tomography using MPI on Heterogeneous Workstation Clusters  

E-Print Network (OSTI)

tomography is a computed tomography method which efficiently acquires projectional data through a single. Introduction Tomographic reconstruction from projections using computed tomography (CT) provides a noninvasive, the projectional data is projected back onto an image buffer with each de- tected ray backprojected in it

Chaudhary, Vipin

69

Reconstruction in tomography with diffracting sources  

E-Print Network (OSTI)

Homogeneous Model . . . . . . . . . . . . . . . . . . . 22 III LIMITED-VIEW THERMOACOUSTIC TOMOGRAPHY1 . . . 24 A. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . 24 1. Analysis of Singularities in Circular Radon Trans- form and Limited-view TAT... . . . . . . . . . . . . . . 26 a. Circular Radon Transform . . . . . . . . . . . . . 26 b. TAT . . . . . . . . . . . . . . . . . . . . . . . . . 27 c. Reconstruction Methods . . . . . . . . . . . . . . 30 2. Numerical Implementation . . . . . . . . . . . . . . . 35 viii CHAPTER...

Xu, Yuan

2005-02-17T23:59:59.000Z

70

Advanced Instrumentation for Positron Emission Tomography [PET  

DOE R&D Accomplishments (OSTI)

This paper summarizes the physical processes and medical science goals that underlay modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost.

Derenzo, S. E.; Budinger, T. F.

1985-04-00T23:59:59.000Z

71

Binary Tomography with Deblurring Stefan Weber1  

E-Print Network (OSTI)

two scenarios of limited-angle binary tomography with data distorted with an unknown convolution: Either the projec- tion data are taken from a blurred object, or the projection data them- selves the projection data before reconstruction (let us call them preprocessing) and then the reconstruction

Schnörr, Christoph

72

Ground-based Microwave Cloud Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Microwave Cloud Tomography Microwave Cloud Tomography Experiment, SGP, May 15-June 15, 2009 Lead Scientist Dong Huang, BNL Co-Investigators Al Gasiewski, UC Boulder Maria Cadeddu, ANL Warren Wiscombe, BNL Radiation Processes Working Group March 30, 2009 multiple radiometers All good cloud radiation modelers should close their airplane window shades so as not to be corrupted by the spectacle of real 3D clouds. - Roger Davies In case you forget to do this, you see 3/30/2009 ARM RPWG 2 Effects of cloud structure on radiation 3/30/2009 ARM RPWG 3 Typical climate model - Cloud fraction & mean water content - Horizontally uniform clouds, no side radiation - Assumption on overlap Courtesy of Bernhard Mayer Cloud structure important to radiation - Cumulus (Benner & Evans 2001, Pincus et al. 2005), deep convection (DiGiuseppe &

73

Efficient and facile delivery of gold nanoparticles in vivo using dissolvable microneedles for contrast-enhanced optical coherence tomography  

E-Print Network (OSTI)

J. G. Fujimoto, “Optical coherence tomography,” Science 254(and imaging using optical coherence tomography,” Nat. Med.J. G. Fujimoto, “Optical coherence tomography for optical

Kim, Chang Soo; Ahn, Yeh-Chan; Wilder-Smith, Petra; Oh, Seajin; Chen, Zhongping; Kwon, Young Jik

2010-01-01T23:59:59.000Z

74

Spectral-domain optical coherence tomography of conjunctival mucosa-associated lymphoid tissue lymphoma with presumed choroidal involvement  

E-Print Network (OSTI)

lymphoid tissue . MALT . Optical coherence tomography . OCTdo not include ocular coherence tomography (OCT). We presentSpectral-domain optical coherence tomography of conjunctival

Williams, Basil K.; Tsui, Irena; McCannel, Tara A.

2010-01-01T23:59:59.000Z

75

AFIP-7 Tomography – 2013 Status Report  

SciTech Connect

This project seeks to assess the geometric stability of the U-Mo monolithic fuel system by evaluating the radiation-induced changes in the AFIP-7 experiment device. Neutron radiography and computed tomography (CT) provide valuable information about the post-irradiation condition of the fuel specimen. Tomographic reconstructions of the AFIP-7 fuel element will be analyzed to assess the geometric condition of the element after irradiation and provide information regarding the condition of the fuel, including gross geometric defects, bowing, twist, plate buckling, cracks, and other defects. The INL, in collaboration with Oregon State University (OSU), Missouri University of Science and Technology (Missouri S&T), and Real Time Tomography, is developing advanced neutron detector systems and tomographic reconstruction techniques to evaluate the AFIP-7 fuel element. Neutron computed tomography using the current neutron radiography technique available at the Neutron Radiography reactor (NRAD) is impractical due to the long time and high cost to produce a set of images for tomographic reconstruction. Advanced neutron radiography systems such as the micro-channel plate (MCP) detector and neutron computed radiography (CR) may reduce the time and cost of acquiring images for neutron CT.

A.E. Craft; W.J. Williams; M.I.K. Abir; D.M. Wachs

2013-10-01T23:59:59.000Z

76

angiographic computed tomography: Topics by E-print Network  

NLE Websites -- All DOE Office Websites (Extended Search)

the development and application of a 4-Dimensional Computed Tomography (4D CT) simulation program. The simulation is used to understand and quantify the sources of image...

77

Time-dependent seismic tomography and its application to the...  

Open Energy Info (EERE)

to the Coso geothermal area, 1996-2006 Abstract Measurements of temporal changes in Earth structure are commonly determined using local earthquake tomography computer programs...

78

Emerging trends in cone-beam computed tomography utilization.  

E-Print Network (OSTI)

?? Utilization of cone-beam computed tomography (CBCT) provides precise and interactive images, which facilitate the diagnosis of dental disease and guided therapy. As with any… (more)

Boyle, Elizabeth M.

2010-01-01T23:59:59.000Z

79

White-Etching Crack Failure Overview, Tomography Analysis, and...  

NLE Websites -- All DOE Office Websites (Extended Search)

White-Etching Crack Failure Overview, Tomography Analysis, and Test Development Presented by Aaron Greco of Argonne National Laboratory at the Wind Turbine Tribology Seminar 2014....

80

Three-Dimensional Thermal Tomography Advances Cancer Treatment...  

NLE Websites -- All DOE Office Websites (Extended Search)

Three-Dimensional Thermal Tomography Advances Cancer Treatment Technology available for licensing: A 3D technique to detect early skin changes due to radiation treatment in breast...

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Direct Sampling Method for Diffusive Optical Tomography  

E-Print Network (OSTI)

In this work, we are concerned with the diffusive optical tomography (DOT) problem in the case when only one or two pairs of Cauchy data is available. We propose a simple and efficient direct sampling method (DSM) to locate inhomogeneities inside a homogeneous background and solve the DOT problem in both full and limited aperture cases. This new method is easy to implement and less expensive computationally. Numerical experiments demonstrate its effectiveness and robustness against noise in the data. This provides a new promising numerical strategy for the DOT problem.

Yat Tin Chow; Kazufumi Ito; Keji Liu; Jun Zou

2014-10-06T23:59:59.000Z

82

Double common-path interferometer for flexible optical probe of optical coherence tomography  

E-Print Network (OSTI)

J. Fujimoto, “Optical coherence tomography,” Science 254(D. E. N. Davies, “Optical coherence-domain reflectometry: afiber common-path optical coherence tomography: sensitivity

Park, Jae Seok; Chen, Zhongping; Jeong, Myung Yung; Kim, Chang-Seok

2012-01-01T23:59:59.000Z

83

High-speed upper-airway imaging using full-range optical coherence tomography  

E-Print Network (OSTI)

Huang et al. , “Optical coherence tomography,” Science 254(endoscopic long-range optical coherence tomogra- phy,” Opt.tracking with optical coherence tomography: proof-of-

Jing, Joseph; Zhang, Jun; Loy, Anthony Chin; Wong, Brian F.; Chen, Zhongping

2012-01-01T23:59:59.000Z

84

E-Print Network 3.0 - angiography computed tomography Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

Solutions Computed Tomography (CTCAT) 3D volume is reconstructed... ) Computer Tomography (CT): Radon-Transformation reconstructs images from projection data-profiles ...

85

XEDS STEM Tomography For 3D Chemical CharacterizationOf Nanoscale...  

NLE Websites -- All DOE Office Websites (Extended Search)

XEDS STEM Tomography For 3D Chemical CharacterizationOf Nanoscale Particles. XEDS STEM Tomography For 3D Chemical CharacterizationOf Nanoscale Particles. Abstract: We present a...

86

E-Print Network 3.0 - artery computed tomography Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

computed tomography Search Powered by Explorit Topic List Advanced Search Sample search results for: artery computed tomography Page: << < 1 2 3 4 5 > >> 1 Abstract Computed...

87

Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem  

SciTech Connect

Neutron radiography and computed tomography are commonly used techniques to non-destructively examine materials. Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions.

William Charlton

2007-07-01T23:59:59.000Z

88

Neutron Stimulated Emission Computed Tomography of Stable Isotopes  

E-Print Network (OSTI)

Neutron Stimulated Emission Computed Tomography of Stable Isotopes Carey E. Floyd Jr.*ab , Calvin North Carolina Keywords: imaging, neutrons, tomography, spectroscopy ABSTRACT Here we report on the development of a new molecular imaging technique using inelastic scattering of fast neutrons. Earlier studies

89

Measuring the Kuroshio Current with ocean acoustic tomography Naokazu Taniguchia)  

E-Print Network (OSTI)

Measuring the Kuroshio Current with ocean acoustic tomography Naokazu Taniguchia) Graduate School 29 April 2013) Ocean current profiling using ocean acoustic tomography (OAT) was conducted proportional to temperature) and current in the ocean (Munk et al., 1995). Other than coastal sea studies (e

Frandsen, Jannette B.

90

Multilevel bioluminescence tomography based on radiative transfer equation  

E-Print Network (OSTI)

Multilevel bioluminescence tomography based on radiative transfer equation Part 2: total variation with both l1 and total- variation norm for bioluminescence tomography based on radiative transfer equation, Radiative Transfer (Dover Publications, 1960). 14. K. M. Case and P. F. PF Zweifel, Linear Transport Theory

Soatto, Stefano

91

Dynamic Computed Tomography, an algebraic reconstruction method with  

E-Print Network (OSTI)

in Grenoble. Finally, I wish to thank the people from the department of International Relations of University whilst improving accuracy. Some of its cur- rect research projects are about dynamic tomography . . . . . . . . . . . . . . . . . . . . . 9 2 Basic tools for Computed Tomography 10 2.1 The Radon Transform

Promayon, Emmanuel

92

Total variation based Fourier reconstruction and regularization for computer tomography  

E-Print Network (OSTI)

of the reconstruted image. Insufficiency of data may be caused by the undersampling of projections, by the limitedTotal variation based Fourier reconstruction and regularization for computer tomography Xiao. Index Terms-- Computer tomography, reconstruction, regular- ization, iterative method, Fourier method

Zhang, Xiaoqun

93

Full-wavelet approach for fluorescence diffuse optical tomography  

E-Print Network (OSTI)

Full-wavelet approach for fluorescence diffuse optical tomography with structured illumination Leonardo da Vinci 32, I-20133 Milan, Italy 3 Centre for Medical Image Computing, University College London); published October 28, 2010 We present a fast reconstruction method for fluorescence optical tomography

Boyer, Edmond

94

Raw Data Compression in Computed Tomography: Noise Shaping  

E-Print Network (OSTI)

Raw Data Compression in Computed Tomography: Noise Shaping Yao Xie (team member: Adam Wang) Project.1 Background X-ray computed tomography (CT) builds on the physical principles of radiography. It uses multiple ring that has a limited data transfer rate. Compression can be used to reduce the data rate through

Xie, Yao

95

Propagation Beam Consideration for 3D THz Computed Tomography  

E-Print Network (OSTI)

Propagation Beam Consideration for 3D THz Computed Tomography B. Recur, 1, J.P. Guillet, 2 I. Manek, "Refraction losses in terahertz computed tomography," Opt. Commun. 283, 2050­2055 (2010). 8. S. Nadar, H, "Accelerated image reconstruction using ordered subsets of projection data," IEEE Trans. Med. Imaging 13, 601

Boyer, Edmond

96

Registration of Planar Film Radiographs with Computed Tomography  

E-Print Network (OSTI)

Registration of Planar Film Radiographs with Computed Tomography Lisa M. Gottesfeld Brown lisabHigh University Bethlehem, PA 18015 Abstract In this paper we describe a method to register Computed Tomography, high resolution, three dimensional, structural med- ical images, such as data from X-ray computed

Boult, Terrance E.

97

Cone-based electrical resistivity tomography Adam Pidlisecky1  

E-Print Network (OSTI)

Cone-based electrical resistivity tomography Adam Pidlisecky1 , Rosemary Knight1 , and Eldad Haber2 and transport of the contaminants. Borehole- based electrical resistivity tomography ERT is a geophysical meth. The measurements yield values of resistance that can be inverted to determine the subsurface electrical

Knight, Rosemary

98

Performance dependence of hybrid x-ray computed tomography/fluorescence molecular  

E-Print Network (OSTI)

Performance dependence of hybrid x-ray computed tomography/fluorescence molecular tomography imaging systems combining x-ray computed tomography (CT) and fluorescence tomography can im- prove Ntziachristos2 1 Department of Electrical and Computer Engineering, Northeastern University, 360 Huntington Ave

Miller, Eric

99

Compact conscious animal positron emission tomography scanner  

DOE Patents (OSTI)

A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

Schyler, David J. (Bellport, NY); O'Connor, Paul (Bellport, NY); Woody, Craig (Setauket, NY); Junnarkar, Sachin Shrirang (Sound Beach, NY); Radeka, Veljko (Bellport, NY); Vaska, Paul (Sound Beach, NY); Pratte, Jean-Francois (Stony Brook, NY); Volkow, Nora (Chevy Chase, MD)

2006-10-24T23:59:59.000Z

100

Computed tomography on small explosive parts  

SciTech Connect

We have investigated three small explosive parts for the Pantex Plant in Amarillo, Texas using computed tomography (CT). A medium resolution, fan beam system was used to test imaging capabilities for small holes drilled into one of the parts, and to identify any inhomogeneities, cracks, voids, and inclusions if present in the other two parts. This system provides volumetric imaging. Its information is qualitative in that is allows us to see interior features but it cannot provide quantitative attenuation data. A second part of the investigation was to perform effective atomic number computed tomography on the parts using energy dispersive spectroscopy methods. We wanted to experimentally identify the {open_quotes}average{close_quotes} chemical composition of the materials in the explosive and its shell and to detect any possible inhomogeneities in composition. A single beam, nuclear spectroscopy based system was used for this work. The radiation source was a silver anode x-ray tube. By measuring x-ray attenuation at specific energies (characteristic lines and narrow bands of continuum) we are able to quantitatively determine linear attenuation coefficients. By using ratios of such measurements, density cancels out and we effectively have ratios of mass attenuation coefficients. Through a look-up scheme of mass attenuation coefficients for different elements, we can determine the weighted average chemical composition, as averaged by x-ray attenuation. We call this averaged composition the effective atomic number ({open_quotes}Z{sub eff}{close_quotes}). We thereby obtain cross sectional images of a parameter related to the averaged chemistry of the object. Such images and the underlying data can reveal, for instance, segregation of explosive and binder.

Ryon, R.W.

1994-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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101

Magnified Weak Lensing Cross Correlation Tomography  

SciTech Connect

This project carried out a weak lensing tomography (WLT) measurement around rich clusters of galaxies. This project used ground based photometric redshift data combined with HST archived cluster images that provide the WLT and cluster mass modeling. The technique has already produced interesting results (Guennou et al, 2010,Astronomy & Astrophysics Vol 523, page 21, and Clowe et al, 2011 to be submitted). Guennou et al have validated that the necessary accuracy can be achieved with photometric redshifts for our purposes. Clowe et al titled "The DAFT/FADA survey. II. Tomographic weak lensing signal from 10 high redshift clusters," have shown that for the **first time** via this purely geometrical technique, which does not assume a standard rod or candle, that a cosmological constant is **required** for flat cosmologies. The intent of this project is not to produce the best constraint on the value of the dark energy equation of state, w. Rather, this project is to carry out a sustained effort of weak lensing tomography that will naturally feed into the near term Dark Energy Survey (DES) and to provide invaluable mass calibration for that project. These results will greatly advance a key cosmological method which will be applied to the top-rated ground-based project in the Astro2020 decadal survey, LSST. Weak lensing tomography is one of the key science drivers behind LSST. CO-I Clowe is on the weak lensing LSST committee, and senior scientist on this project, at FNAL James Annis, plays a leading role in the DES. This project has built on successful proposals to obtain ground-based imaging for the cluster sample. By 1 Jan, it is anticipated the project will have accumulated complete 5-color photometry on 30 (or about 1/3) of the targeted cluster sample (public webpage for the survey is available at http://cencos.oamp.fr/DAFT/ and has a current summary of the observational status of various clusters). In all, the project has now been awarded the equivalent of over 60 nights on 4-m class telescopes, which gives concrete evidence of strong community support for this project. The WLT technique is based on the dependence of the gravitational shear signal on the angular diameter distances between the observer, the lens, and the lensed galaxy to measure cosmological parameters. By taking the ratio of measured shears of galaxies with different redshifts around the same lens, one obtains a measurement of the ratios of the angular diameter distances involved. Making these observations over a large range of lenses and background galaxy redshifts will measure the history of the expansion rate of the universe. Because this is a purely geometric measurement, it is insensitive to any form of evolution of objects or the necessity to understand the physics in the early universe. Thus, WLT was identified by the Dark Energy Task Force as perhaps the best method to measure the evolution of DE. To date, however, the conjecture of the DETF has not been experimentally verified, but will be by the proposed project. The primary reason for the lack of tomography measurements is that one must have an exceptional data-set to attempt the measurement. One needs both extremely good seeing (or space observations) in order to minimize the point spread function smearing corrections on weak lensing shear measurements and deep, multi-color data, from B to z, to measure reliable photometric redshifts of the background galaxies being lensed (which are typically too faint to obtain spectroscopic redshifts). Because the entire process from multi-drizzling the HST images, and then creating shear maps, to gathering the necessary ground based observations, to generating photo-zs and then carrying out the tomography is a complicated task, until the creation of our team, nobody has taken the time to connect all the levels of expertise necessary to carry out this project based on HST archival data. Our data are being used in 2 Ph.D. theses. Kellen Murphy, at Ohio University, is using the tomography data along with simulations in a thesis expected to be completed in Jun

Ulmer, Melville P., Clowe, Douglas I.

2010-11-30T23:59:59.000Z

102

Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators  

Open Energy Info (EERE)

Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Details Activities (8) Areas (4) Regions (0) Abstract: Body and surface wave tomography are two of the primary methods for estimation of regional scale seismic velocity variations. Seismic velocity is affected by temperature and rock composition in complex ways, but when combined with geologic and structural maps, relative temperature can in some cases be estimated. We present preliminary tomographic models for compressional and shear-wave velocity using local and regional earthquakes recorded by Earthscope Transportable Array stations, network

103

Three-Dimensional Thermal Tomography Advances Cancer Treatment...  

NLE Websites -- All DOE Office Websites (Extended Search)

Three-Dimensional Thermal Tomography Advances Cancer Treatment (ANL-IN-07-170) Argonne National Laboratory Contact ANL About This Technology

Change in temperature over time...

104

Traveltime tomography in anisotropic media—I. Theory  

Science Journals Connector (OSTI)

......Traveltime tomography in anisotropic media-II. Application...technique for weakly anisotropic velocity, Geophysics...Velocity anisotropy in shale determined from crosshole...technique for weakly anisotropic velocity, Geophysics...Velocity anisotropy in shale determined from crosshole......

C. H. Chapman; R. G. Pratt

1992-04-01T23:59:59.000Z

105

Functional lung imaging in humans using Positron Emission Tomography  

E-Print Network (OSTI)

This thesis deals with a method of functional lung imaging using Positron Emission Tomography (PET). In this technique, a radioactive tracer, nitrogen-13, is dissolved in saline solution, and injected into a peripheral ...

Layfield, Dominick, 1971-

2003-01-01T23:59:59.000Z

106

Electrical capacitance volume tomography (ECVT) applied to bubbling fluid beds  

SciTech Connect

These presentation visuals illustrate the apparatus and method for applying Electrical Capacitance Volume Tomography (ECVT) to bubbling fluid beds to their solid fraction and bubble properties. Results are compared to estimated values.

Weber, J., Mei, J.

2012-01-01T23:59:59.000Z

107

Scattered neutron tomography based on a neutron transport problem  

E-Print Network (OSTI)

scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

Scipolo, Vittorio

2005-11-01T23:59:59.000Z

108

NEURAL NETWORKS FOR DISCRETE TOMOGRAPHY K.J. Batenburg a  

E-Print Network (OSTI)

NEURAL NETWORKS FOR DISCRETE TOMOGRAPHY K.J. Batenburg a W.A. Kosters b a Mathematical Institute of crystalline solids at atomic resolution from electron microscopic images can be considered the "holy grail

Kosters, Walter

109

Thickness Estimation with Optical Coherence Tomography and Statistical Decision Theory  

Science Journals Connector (OSTI)

We implement a maximum-likelihood (ML) estimator to interpret Optical Coherence Tomography (OCT) data, based on a Fourier-Domain OCT and a two-interface tear film model. We use the...

Huang, Jinxin; Clarkson, Eric; Kupinski, Matthew; Rolland, Jannick P

110

Frequency comb swept lasers for optical coherence tomography  

E-Print Network (OSTI)

We demonstrate a frequency comb (FC) swept laser and a frequency comb Fourier domain mode locked (FC-FDML) laser for applications in optical coherence tomography (OCT). The fiber-based FC swept lasers operate at a sweep ...

Tsai, Tsung-Han

111

Ultrahigh speed optical coherence tomography for ophthalmic imaging applications  

E-Print Network (OSTI)

Optical coherence tomography (OCT) is a non-contact, non-invasive, micron-scale optical imaging technology that has become a standard clinical tool in ophthalmology. Fourier domain OCT detection methods have enabled higher ...

Liu, Jonathan Jaoshin

2014-01-01T23:59:59.000Z

112

Breast ultrasound tomography with total-variation regularization  

SciTech Connect

Breast ultrasound tomography is a rapidly developing imaging modality that has the potential to impact breast cancer screening and diagnosis. A new ultrasound breast imaging device (CURE) with a ring array of transducers has been designed and built at Karmanos Cancer Institute, which acquires both reflection and transmission ultrasound signals. To extract the sound-speed information from the breast data acquired by CURE, we have developed an iterative sound-speed image reconstruction algorithm for breast ultrasound transmission tomography based on total-variation (TV) minimization. We investigate applicability of the TV tomography algorithm using in vivo ultrasound breast data from 61 patients, and compare the results with those obtained using the Tikhonov regularization method. We demonstrate that, compared to the Tikhonov regularization scheme, the TV regularization method significantly improves image quality, resulting in sound-speed tomography images with sharp (preserved) edges of abnormalities and few artifacts.

Huang, Lianjie [Los Alamos National Laboratory; Li, Cuiping [KARMANOS CANCER INSTIT.; Duric, Neb [KARMANOS CANCER INSTIT

2009-01-01T23:59:59.000Z

113

Computational Inversion of Electron Tomography Images -Gradient Flows  

E-Print Network (OSTI)

Computational Inversion of Electron Tomography Images Using L2 -Gradient Flows Guoliang Xu 1) Ming Computing Institute of Computational Mathematics, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100190, China 2) Department of Computer Sciences and Institute

Texas at Austin, University of

114

ELECTRICAL IMPEDANCE TOMOGRAPHY ON A RESISTIVE NETWORK WITH INTERNAL CURRENTS  

E-Print Network (OSTI)

ELECTRICAL IMPEDANCE TOMOGRAPHY ON A RESISTIVE NETWORK WITH INTERNAL CURRENTS YONG JUNG KIM AND MIN resonance image, electrical density image, electrical impedance tomog- raphy, resistive network, anisotropic from internal currents and the boundary conductivity. An electrically conducting body is discretized

Kim, Yong Jung

115

Quantification of airway thickness changes in smoke-inhalation injury using in-vivo 3-D endoscopic frequency-domain optical coherence tomography  

E-Print Network (OSTI)

J. G. Fujimoto, “Optical coherence tomography,” Science 254(endomicroscopy using optical coherence tomography,” Nat.Fourier domain optical coherence tomography,” Opt. Express

2011-01-01T23:59:59.000Z

116

Amorphous silicon detectors in positron emission tomography  

SciTech Connect

The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs.

Conti, M. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy) Lawrence Berkeley Lab., CA (USA)); Perez-Mendez, V. (Lawrence Berkeley Lab., CA (USA))

1989-12-01T23:59:59.000Z

117

Portable Digital Radiography and Computed Tomography Manual  

SciTech Connect

This user manual describes the function and use of the portable digital radiography and computed tomography (DRCT) scanner. The manual gives a general overview of x-ray imaging systems along with a description of the DRCT system. An inventory of the all the system components, organized by shipping container, is also included. In addition, detailed, step-by-step procedures are provided for all of the exercises necessary for a novice user to successfully collect digital radiographs and tomographic images of an object, including instructions on system assembly and detector calibration and system alignment. There is also a short section covering the limited system care and maintenance needs. Descriptions of the included software packages, the DRCT Digital Imager used for system operation, and the DRCT Image Processing Interface used for image viewing and tomographic data reconstruction are given in the appendixes. The appendixes also include a cheat sheet for more experienced users, a listing of known system problems and how to mitigate them, and an inventory check-off sheet suitable for copying and including with the machine for shipment purposes.

Not Available

2007-11-01T23:59:59.000Z

118

Investigating Jet Mixing Using Electrical Resistance Tomography  

Science Journals Connector (OSTI)

Coaxial jet and side entry mixers are used in a wide range of industries for a variety of processes including precipitation polymerization and neutralization duties. Jet mixers are characterized by short contact times between the fluids and can be operated continuously or semi?batch. Coaxial and side entry jets can be designed in order to deliver rapid turbulent mixing using short sections of pipeline. As the energy required for mixing is provided by the addition stream the process?side pressure drop required for homogeneity is very low. A key design parameter for jet mixers is the mixing length the length of pipe downstream of the injection point required to achieve a given degree of homogeneity. The mixing length can be affected by the addition geometry (for example coaxial or side entry) orifice size and shape operating conditions and material properties. This paper presents the use of Electrical Resistance Tomography (ERT) to monitor jet mixing via the addition of a conductivity tracer through coaxial and side entry jets. Multiple ERT sensors are fitted along the pipe downstream of the jet addition point. The ERT sensors enable real time non?invasive measurement of conductivity within the pipe furnishing approximately 2500 conductivity measurements per ERT sensor when modeled independently in 3D. The effect of secondary (main pipe) flow rate and jet configuration on the nature of the tracer plume evolution and axial mixing is determined using this technique.

D. R. Stephenson; M. Cooke; A. Kowalski; T. A. York

2007-01-01T23:59:59.000Z

119

A Detector for Proton Computed Tomography  

SciTech Connect

Radiation therapy is a widely recognized treatment for cancer. Energetic protons have distinct features that set them apart from photons and make them desirable for cancer therapy as well as medical imaging. The clinical interest in heavy ion therapy is due to the fact that ions deposit almost all of their energy in a sharp peak – the Bragg peak- at the very end of their path. Proton beams can be used to precisely localize a tumor and deliver an exact dose to the tumor with small doses to the surrounding tissue. Proton computed tomography (pCT) provides direct information on the location on the target tumor, and avoids position uncertainty caused by treatment planning based on imaging with X-ray CT. The pCT project goal is to measure and reconstruct the proton relative stopping power distribution directly in situ. To ensure the full advantage of cancer treatment with 200 MeV proton beams, pCT must be realized.

Blazey, G.; et al.,

2013-12-06T23:59:59.000Z

120

Allan Cormack, Computerized Axial Tomography (CAT), and Magnetic Resonance  

NLE Websites -- All DOE Office Websites (Extended Search)

Allan M. Cormack, Computerized Axial Tomography (CAT) Allan M. Cormack, Computerized Axial Tomography (CAT) and Magnetic Resonance Imaging (MRI) Resources with Additional Information magnetic resonance imaging system Computed axial tomography, commonly known as CAT scanning, was introduced in 1972. During a CAT scan, a large coil of x-ray tubes rotates around the patient's body, taking x-rays from all angles. A computer integrates all of these x-rays into a single, three-dimensional image on a television screen. The data can be saved on the computer. Allan M. Cormack, a high energy physicist at Tufts University, shared the 1979 Nobel Prize in Physiology and Medicine for his key work in developing the methods for CAT scanners. At the time of development, these methods were widely regarded as the most significant advance in medical radiography since the 1895 discovery of x-rays.

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Dictionary-Learning-Based Reconstruction Method for Electron Tomography  

E-Print Network (OSTI)

Electron tomography usually suffers from so called missing wedge artifacts caused by limited tilt angle range. An equally sloped tomography (EST) acquisition scheme (which should be called the linogram sampling scheme) was recently applied to achieve 2.4-angstrom resolution. On the other hand, a compressive sensing-inspired reconstruction algorithm, known as adaptive dictionary based statistical iterative reconstruction (ADSIR), has been reported for x-ray computed tomography. In this paper, we evaluate the EST, ADSIR and an ordered-subset simultaneous algebraic reconstruction technique (OS-SART), and compare the ES and equally angled (EA) data acquisition modes. Our results show that OS-SART is comparable to EST, and the ADSIR outperforms EST and OS-SART. Furthermore, the equally sloped projection data acquisition mode has no advantage over the conventional equally angled mode in the context.

Liu, Baodong; Verbridge, Scott S; Sun, Lizhi; Wang, Ge

2013-01-01T23:59:59.000Z

122

Microwave-induced thermoacoustic tomography: applications and corrections for the effects of acoustic heterogeneities  

E-Print Network (OSTI)

This research is primarily focused on developing potential applications for microwaveinduced thermoacoustic tomography and correcting for image degradations caused by acoustic heterogeneities. Microwave-induced thermoacoustic tomography was first...

Jin, Xing

2009-05-15T23:59:59.000Z

123

E-Print Network 3.0 - agent-enhanced computed tomography Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

computed tomography Page: << < 1 2 3 4 5 > >> 1 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: problems X-ray tomography...

124

E-Print Network 3.0 - advanced computed tomography Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

advanced computed tomography Page: << < 1 2 3 4 5 > >> 1 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: problems X-ray tomography...

125

Comparing Time Domain Reflectometry and Electrical Resistivity Tomography Measurements for Estimating Soil Water Distribution  

E-Print Network (OSTI)

511 Comparing Time Domain Reflectometry and Electrical Resistivity Tomography Measurements compared with electrical resistivity tomography (ERT) measurements along the same cross's interior for the measurements. However, determining the soil water content from the resulting electrical

Sailhac, Pascal

126

Multiplexed absorption tomography with calibration-free wavelength modulation spectroscopy  

SciTech Connect

We propose a multiplexed absorption tomography technique, which uses calibration-free wavelength modulation spectroscopy with tunable semiconductor lasers for the simultaneous imaging of temperature and species concentration in harsh combustion environments. Compared with the commonly used direct absorption spectroscopy (DAS) counterpart, the present variant enjoys better signal-to-noise ratios and requires no baseline fitting, a particularly desirable feature for high-pressure applications, where adjacent absorption features overlap and interfere severely. We present proof-of-concept numerical demonstrations of the technique using realistic phantom models of harsh combustion environments and prove that the proposed techniques outperform currently available tomography techniques based on DAS.

Cai, Weiwei; Kaminski, Clemens F., E-mail: cfk23@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB2 3RA (United Kingdom)

2014-04-14T23:59:59.000Z

127

Inverse scattering for frequency-scanned full-field optical coherence tomography  

E-Print Network (OSTI)

Inverse scattering for frequency-scanned full-field optical coherence tomography Daniel L. Marks-field optical coherence tomography (OCT) is able to image an entire en face plane of scatterers simulta- neously: 100.3010, 110.4500. 1. INTRODUCTION The capabilities of optical coherence tomography1,2 (OCT

Bhargava, Rohit

128

LimitedAngle Computed Tomography for Sandwich Structures using Data Fusion  

E-Print Network (OSTI)

1 Limited­Angle Computed Tomography for Sandwich Structures using Data Fusion Jeffrey E. Boyd and limited­angle computed­tomography (CT) are ill­posed problems, but where conventional CT has a small null. #12; 2 1. INTRODUCTION This paper presents a novel method for limited­angle computed tomography (CT

Boyd, Jeffrey E.

129

Reduction of Metal Artifacts in Computed Tomographies for the Planning and Simulation of Radiation Therapy  

E-Print Network (OSTI)

tomographies (CT). Compared to simulated CT projection data, real measurements allowed less improvementsReduction of Metal Artifacts in Computed Tomographies for the Planning and Simulation of Radiation and numerical stability. 1. INTRODUCTION In radiation therapy, computed tomographies are used for patient

Zerfowski, Detlef

130

Robust statistical reconstruction for charged particle tomography  

DOE Patents (OSTI)

Systems and methods for charged particle detection including statistical reconstruction of object volume scattering density profiles from charged particle tomographic data to determine the probability distribution of charged particle scattering using a statistical multiple scattering model and determine a substantially maximum likelihood estimate of object volume scattering density using expectation maximization (ML/EM) algorithm to reconstruct the object volume scattering density. The presence of and/or type of object occupying the volume of interest can be identified from the reconstructed volume scattering density profile. The charged particle tomographic data can be cosmic ray muon tomographic data from a muon tracker for scanning packages, containers, vehicles or cargo. The method can be implemented using a computer program which is executable on a computer.

2013-10-08T23:59:59.000Z

131

Magnetospheric Constellation and Tomography Mission Concept R. E. Ergun1*  

E-Print Network (OSTI)

Magnetospheric Constellation and Tomography Mission Concept R. E. Ergun1* , D. E. Larson1 , T. Phan]. The interaction between the solar wind and mag- netosphere results with energy and mass transfer across magnetic and stored in the magnetotail. A plasma sheet appears between the two lobes of the magnetotail where energy

California at Berkeley, University of

132

ADVANCES IN IMAGING AND ELECTRON PHYSICS, VOL. 128 Quantum Tomography  

E-Print Network (OSTI)

ADVANCES IN IMAGING AND ELECTRON PHYSICS, VOL. 128 Quantum Tomography G. MAURO D'ARIANO, MATTEO G .............. 277 205 Copyright 9 2003 Elsevier Inc. All r~crhte r~r~r~ #12;206 MAURO D'ARIANO ET AL. VII

D'Ariano, Giacomo Mauro

133

Roadmap: Radiologic Imaging Sciences -Computed Tomography (with AAS Radiologic Technology) -  

E-Print Network (OSTI)

Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-CTRT] Regional College Catalog Year: 2013-2014 Page 1 of 2 | Last Updated: 30-Apr-13/LNHD This roadmap is a recommended semester

Sheridan, Scott

134

Roadmap: Radiologic Imaging Sciences -Computed Tomography (with AAS Radiologic Technology) -  

E-Print Network (OSTI)

Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-CTRT] Regional College Catalog Year: 2012-2013 Page 1 of 2 | Last Updated: 25-Oct-12/LNHD This roadmap is a recommended semester

Sheridan, Scott

135

Constraints on mantle convection from seismic tomography and flow modeling  

E-Print Network (OSTI)

In this thesis I combine high resolution seismic tomography and realistic flow modeling to constrain mantle convection. The bulk of the data used in the tomographic imaging are millions of P, pP and pwP travel time residuals, ...

Kárason, Hrafnkell, 1970-

2002-01-01T23:59:59.000Z

136

A SIGNAL SYNTHESIS PROCEDURE DESIGNED FOR DISCREET OCEAN ACOUSTIC TOMOGRAPHY  

E-Print Network (OSTI)

the detection probability of active emis- sions by a nearby unknown interceptor. Finally, this procedure is ap in ship noise with the constraint to have an accurate estimation of the channel parameters. Results tomography, parameter estimation, sig- nal detection, optimization, performance analysis 1. INTRODUCTION

Boyer, Edmond

137

A new concept of ocean acoustic tomography Lionel CROS(1)  

E-Print Network (OSTI)

a synthetic signal in ship noise with the con- straint to have an accurate estimation of the channel: discreet acoustic tomography, estimation, detection, optimization, performance analysis. R´ESUM´E COURT: La disc`ete, estimation, d´etection, optimisation, analyse de perfor- mance. 1 INTRODUCTION Ocean acoustic

Boyer, Edmond

138

Adaptive optics enhanced simultaneous en-face optical coherence tomography  

E-Print Network (OSTI)

Adaptive optics enhanced simultaneous en-face optical coherence tomography and scanning laser ophthalmoscopy David Merino and Chris Dainty Applied Optics Group, Department of Experimental Physics, National and Adrian Gh. Podoleanu Applied Optics Group, School of Physical Sciences, University of Kent at Canterbury

Dainty, Chris

139

Spherical radon transforms and mathematical problems of thermoacoustic tomography  

E-Print Network (OSTI)

The spherical Radon transform (SRT) integrates a function over the set of all spheres with a given set of centers. Such transforms play an important role in some newly developing types of tomography as well as in several areas of mathematics...

Ambartsoumian, Gaik

2009-06-02T23:59:59.000Z

140

Neutrino tomography: Tevatron mapping versus the neutrino sky  

Science Journals Connector (OSTI)

... adequate reconstruction for noninvasive imaging in medicine. Geophysical densities follow from the mapping of the Radon or Fourier transform of certain neutrino projections, and not from the Volkova-Zatsepin scheme, ... problem was first addressed by Radon24 who derived what has now become known as the Radon transform. Tomography10'19'20'25 can be defined as reconstructive imaging by means of ...

Thomas L. Wilson

1984-05-03T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

3-D seismic tomography of the Adelaide fold belt  

Science Journals Connector (OSTI)

......the major factor. Temperature-induced P-wave...which smoothes the temperature contrast, resulting...structure of the eastern Snake River Plain and its...1996. Upper mantle temperatures from teleseismic tomography...implications for regolith development, 3rd Australian Regolith......

Peter Clifford; Stewart Greenhalgh; Greg Houseman; Frank Graeber

2008-01-01T23:59:59.000Z

142

3D Tomography from Few Projections in Experimental Fluid Dynamics  

E-Print Network (OSTI)

3D Tomography from Few Projections in Experimental Fluid Dynamics Stefania Petra, Andreas Schr projections due to both limited optical access to wind and water tunnels and cost S. Petra, C. Schn projection data. The latter are the pixel entries in the recorded 2D images that represent the integration

Schnörr, Christoph

143

Volumetric Reconstruction in the MicroCAT Tomography System  

E-Print Network (OSTI)

of projection data . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.2 Illustration of Feldkamp filteredVolumetric Reconstruction in the MicroCAT Tomography System A Thesis Presented for the Master essential data and an intimate knowledge of the MicroCAT system. Dr. Sam Jordan of the University

Cates, Josh

144

Bayesian Image Reconstruction for Transmission Tomography Using Deterministic Annealing  

E-Print Network (OSTI)

and non-medical applications, however, the measured projection data are photon limited and the imaging;1 INTRODUCTION Transmission tomography is perhaps most familiar in its medical guise as CT (computed tomogra- phy procedure. Because of the relatively high dose in conventional CT, the measured projection data contain

Rangarajan, Anand

145

Chapter 7 - Horizontally Integrated Remote Measurements of Ocean Currents Using Acoustic Tomography Techniques  

Science Journals Connector (OSTI)

Abstract This chapter begins with a discussion of the comparative difficulty of measuring horizontally integrated subsurface oceanic current and vorticity measurements. This is followed by a discussion of computer-assisted tomography techniques used in the medical, geophysical, and seismic branches of science and their adaptation and extension to acoustic tomography for subsurface oceanographic investigations. In particular, the following aspects pertaining to the application of acoustic methods for probing the oceans’ interior water temperature and current structure, as well as their adaptations for measuring horizontally averaged water currents from straits, coastal water bodies, estuaries, and rivers, are addressed: (1) one-way tomography, (2) two-way tomography (reciprocal tomography), (3) acoustic tomographic measurements from straits, (4) coastal acoustic tomography (CAT), (5) river acoustic tomography (RAT), (6) acoustic tomographic measurements of vorticity, and (7) horizontally integrated current measurements using space-time acoustic scintillation analysis technique.

Antony Joseph

2014-01-01T23:59:59.000Z

146

Resistivity Tomography At Silver Peak Area (DOE GTP) | Open Energy  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Resistivity Tomography At Silver Peak Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Single-Well and Cross-Well Resistivity At Silver Peak Area (DOE GTP) Exploration Activity Details Location Silver Peak Area Exploration Technique Single-Well and Cross-Well Resistivity Activity Date Usefulness not indicated DOE-funding Unknown References (1 January 2011) GTP ARRA Spreadsheet Retrieved from "http://en.openei.org/w/index.php?title=Resistivity_Tomography_At_Silver_Peak_Area_(DOE_GTP)&oldid=689883" Categories:

147

Using electrical impedance tomography to map subsurface hydraulic conductivity  

DOE Patents (OSTI)

The use of Electrical Impedance Tomography (EIT) to map subsurface hydraulic conductivity. EIT can be used to map hydraulic conductivity in the subsurface where measurements of both amplitude and phase are made. Hydraulic conductivity depends on at least two parameters: porosity and a length scale parameter. Electrical Resistance Tomography (ERT) measures and maps electrical conductivity (which can be related to porosity) in three dimensions. By introducing phase measurements along with amplitude, the desired additional measurement of a pertinent length scale can be achieved. Hydraulic conductivity controls the ability to flush unwanted fluid contaminants from the surface. Thus inexpensive maps of hydraulic conductivity would improve planning strategies for subsequent remediation efforts. Fluid permeability is also of importance for oil field exploitation and thus detailed knowledge of fluid permeability distribution in three-dimension (3-D) would be a great boon to petroleum reservoir analysts.

Berryman, James G. (Danville, CA); Daily, William D. (Livermore, CA); Ramirez, Abelardo L. (Pleasanton, CA); Roberts, Jeffery J. (Livermore, CA)

2000-01-01T23:59:59.000Z

148

Low-cost diffuse optical tomography for the classroom  

Science Journals Connector (OSTI)

Diffuse optical tomography (DOT) is an emerging imaging modality with potential applications in oncology neurology and other clinical areas. It allows the non-invasive probing of the tissue function using relatively inexpensive and safe instrumentation. An educational laboratory setup of a DOT system could be used to demonstrate how photons propagate through tissues basics of medical tomography and the concepts of multiple scattering and absorption. Here we report a DOT setup that could be introduced to the advanced undergraduate or early graduate curriculum using inexpensive and readily available tools. The basis of the system is the LEGO Mindstorms NXT platform which controls the light sources the detectors (photo-diodes) a mechanical 2D scanning platform and the data acquisition. A basic tomographic reconstruction is implemented in standard numerical software and 3D images are reconstructed. The concept was tested and developed in an educational environment that involved a high-school student and a group of post-doctoral fellows.

Taisuke Minagawa; Peyman Zirak; Udo M. Weigel; Anna K. Kristoffersen; Nicolas Mateos; Alejandra Valencia; Turgut Durduran

2012-01-01T23:59:59.000Z

149

Quantum tomography meets dynamical systems and bifurcations theory  

SciTech Connect

A powerful tool for studying geometrical problems in Hilbert spaces is developed. We demonstrate the convergence and robustness of our method in every dimension by considering dynamical systems theory. This method provides numerical solutions to hard problems involving many coupled nonlinear equations in low and high dimensions (e.g., quantum tomography problem, existence and classification of Pauli partners, mutually unbiased bases, complex Hadamard matrices, equiangular tight frames, etc.). Additionally, this tool can be used to find analytical solutions and also to implicitly prove the existence of solutions. Here, we develop the theory for the quantum pure state tomography problem in finite dimensions but this approach is straightforwardly extended to the rest of the problems. We prove that solutions are always attractive fixed points of a nonlinear operator explicitly given. As an application, we show that the statistics collected from three random orthonormal bases is enough to reconstruct pure states from experimental (noisy) data in every dimension d ? 32.

Goyeneche, D., E-mail: dardo.goyeneche@cefop.udec.cl [Departamento de Fisíca, Universidad de Concepción, Casilla 160-C, Concepción, Chile and Center for Optics and Photonics, Universidad de Concepción, Casilla 4012, Concepción (Chile); Torre, A. C. de la [Departamento de Física, Universidad Nacional de Mar del Plata, IFIMAR-CONICET, Dean Funes 3350, 7600 Mar del Plata (Argentina)

2014-06-15T23:59:59.000Z

150

Coral Extension Rate Analysis Using Computed Axial Tomography  

E-Print Network (OSTI)

CORAL EXTENSION RATE ANALYSIS USING COMPUTED AXIAL TOMOGRAPHY A Thesis by ELEANOR ANN YUDELMAN Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE Chair of Committee, Niall Slowey Committee Members, Deborah Thomas Benjamin Giese George P. Schmahl Head of Department, Deborah Thomas May 2014 Major Subject: Oceanography Copyright 2014 Eleanor Ann Yudelman ii ABSTRACT...

Yudelman, Eleanor Ann

2014-01-10T23:59:59.000Z

151

Recent developments in guided wave travel time tomography  

SciTech Connect

The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections. Guided wave tomography had been developed to create a map of the wall thickness using the travel times of guided waves. It can be used for both monitoring and for inspection of pipe-segments that are difficult to access, for instance at the location of pipe-supports. An important outcome of the tomography is the minimum remaining wall thickness, as this is critical in the scheduling of a replacement of the pipe-segment. In order to improve the sizing accuracy we have improved the tomography scheme. A number of major improvements have been realized allowing to extend the application envelope to pipes with a larger wall thickness and to larger distances between the transducer rings. Simulation results indicate that the sizing accuracy has improved and that is now possible to have a spacing of 8 meter between the source-ring and the receiver-ring. Additionally a reduction of the number of sensors required might be possible as well.

Zon, Tim van; Volker, Arno [TNO, Stieltjesweg 1, P.O. box 155 2600 AD Delft (Netherlands)

2014-02-18T23:59:59.000Z

152

Real Time Tomography at the Swiss Light Source  

SciTech Connect

The penetrating power of X-rays coupled with the high flux of 3rd generation synchrotron sources makes X-ray tomography to excel among fast imaging methods . To exploit this asset of synchrotron sources is the motivation for setting up an ultra-fast tomography endstation at the TOMCAT beamline. The state of the art instruments at synchrotron sources offer routinely a temporal resolution of tens of seconds in tomography. For a number of applications, for example biomedical studies, the relevant time scales (breathing, heartbeat) are rather in the range of 0.5-2 seconds. To overcome motion artifacts when imaging such systems a new ultra-fast tomographic data acquisition scheme is being developed at the TOMCAT beamline. We can acquire a full set of projections at sub-second timescale in monochromatic or white-beam configuration. We present a feasibility study with the ultimate aim to achieve sub-second temporal resolution in 3D without significant deterioration of the spatial resolution. For the first time, the 3D dynamics of the very early stages of a quickly aging liquid foam can be visualised with high quality and sufficiently large field of view.

Mokso, R.; Marone, F. [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen (Switzerland); Stampanoni, M. [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen (Switzerland); Institute for Biomedical Engineering, University and ETH Zurich, Zurich (Switzerland)

2010-06-23T23:59:59.000Z

153

Software-defined Radio Based Wireless Tomography: Experimental Demonstration and Verification  

SciTech Connect

This letter presents an experimental demonstration of software-defined-radio-based wireless tomography using computer-hosted radio devices called Universal Software Radio Peripheral (USRP). This experimental brief follows our vision and previous theoretical study of wireless tomography that combines wireless communication and RF tomography to provide a novel approach to remote sensing. Automatic data acquisition is performed inside an RF anechoic chamber. Semidefinite relaxation is used for phase retrieval, and the Born iterative method is utilized for imaging the target. Experimental results are presented, validating our vision of wireless tomography.

Bonior, Jason D [ORNL; Hu, Zhen [Tennessee Technological University; Guo, Terry N. [Tennessee Technological University; Qiu, Robert C. [Tennessee Technological University; Browning, James P. [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Wicks, Michael C. [University of Dayton Research Institute

2015-01-01T23:59:59.000Z

154

E-Print Network 3.0 - aids computed tomography Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

of Mathematics, Tufts University Collection: Mathematics 2 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: problems X-ray tomography...

155

E-Print Network 3.0 - attenuated vector tomography Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Kansas State University Collection: Mathematics 2 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: Optical Tomography Novel...

156

Video-rate fluorescence diffuse optical tomography for in vivo sentinel lymph node imaging  

Science Journals Connector (OSTI)

We have developed a fiber-based, video-rate fluorescence diffuse optical tomography (DOT) system for noninvasive in vivo sentinel lymph node (SLN) mapping. Concurrent acquisition of...

Solomon, Metasebya; White, Brian R; Nothdruft, Ralph E; Akers, Walter; Sudlow, Gail; Eggebrecht, Adam T; Achilefu, Samuel; Culver, Joseph P

2011-01-01T23:59:59.000Z

157

Quantitative and dynamic measurements of biological fresh samples with X-ray phase contrast tomography  

Science Journals Connector (OSTI)

Quantitative measurements of biological fresh samples based on three-dimensional densitometry using X-ray phase contrast tomography are presented.

Hoshino, M.

2014-10-08T23:59:59.000Z

158

Hydraulic conductivity imaging from 3-D transient hydraulic tomography at several pumping/observation densities  

E-Print Network (OSTI)

of transport and design and operation of ground- water remediation systems, are crucially dependent transient hydraulic tomography at several pumping/observation densities, Water Resour. Res., 49, 7311

Barrash, Warren

159

Mapping higher-order brain function and resting-state networks with diffuse optical tomography  

Science Journals Connector (OSTI)

We present integrative advances in high-density diffuse optical tomography imaging arrays, large field-of-view instrumentation, and anatomical head modeling. The system was tested by...

Eggebrecht, Adam T; Ferradal, Silvina L; Robichaux-Viehoever, Amy; Hassanpour, Mahlega S; Dehghani, Hamid; Snyder, Abraham; Hershey, Tamara; Culver, Joseph P

160

Velocity Variation Assessment of Red Blood Cell Aggregation with Spectral Domain Doppler Optical Coherence Tomography  

E-Print Network (OSTI)

J. G. Fujimoto. Optical coherence tomog- raphy. Science 254:spectral domain low coherence interferometry and retinalsedimentation on optical coherence tomography signals from

Xu, Xiangqun; Yu, Lingfeng; Chen, Zhongping

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Four-dimensional optical coherence tomography imaging of total liquid ventilated rats  

Science Journals Connector (OSTI)

Optical coherence tomography (OCT) can be utilized for the spatially and temporally resolved visualization of alveolar tissue and its dynamics in rodent models, which allows the...

Kirsten, Lars; Schnabel, Christian; Gaertner, Maria; Koch, Edmund

162

Quantitative measurements of strain and birefringence with common-path polarization-sensitive optical coherence tomography  

Science Journals Connector (OSTI)

We demonstrate the first system for optical coherence tomography (OCT) that enables simultaneous measurement of quantitative birefringence and strain in biological samples using a...

Marvdashti, Tahereh; Duan, Lian; Lurie, Kristen L; Smith, Gennifer T; Ellerbee, Audrey K

2014-01-01T23:59:59.000Z

163

3D Reconstruction of Intricate Archean Microbial Structures Using Neutron Computed Tomography and Serial SectioningIN43B-0331 Abstract Project Goals  

E-Print Network (OSTI)

Tomography and Serial SectioningIN43B-0331 Abstract Project Goals Background Methods Neutron Computed using both serial sectioning and neutron computed tomography (NCT). Reconstruction techniques vary mechanisms for ancient microbial communities Neutron Computed Tomography Serial Sectioning Samples were

Hamann, Bernd

164

Remote Tomography Via von Neumann-Arthurs-Kelly Interaction  

E-Print Network (OSTI)

Teleportation usually involves entangled particles 1,2 shared by Alice and Bob, Bell-state measurement on particle 1 and system particle by Alice, classical communication to Bob, and unitary transformation by Bob on particle 2. We propose a novel method: interaction-based remote tomography. Alice arranges an entanglement generating von Neumann-Arthurs-Kelly interaction between the system and two apparatus particles, and then teleports the latter to Bob. Bob reconstructs the unknown initial state of the system not received by him by quadrature measurements on the apparatus particles .

S. M. Roy; Abhinav Deshpande; Nitica Sakharwade

2013-08-23T23:59:59.000Z

165

Pulsed homodyne Gaussian quantum tomography with low detection efficiency  

E-Print Network (OSTI)

Pulsed homodyne quantum tomography usually requires a high detection efficiency limiting its applicability in quantum optics. Here, it is shown that the presence of low detection efficiency ($<50\\%$) does not prevent the tomographic reconstruction of quantum states of light, specifically, of Gaussian type. This result is obtained by applying the so-called "minimax" adaptive reconstruction of the Wigner function to pulsed homodyne detection. In particular, we prove, by both numerical and real experiments, that an effective discrimination of different Gaussian quantum states can be achieved. Our finding paves the way to a more extensive use of quantum tomographic methods, even in physical situations in which high detection efficiency is unattainable.

Martina Esposito; Fabio Benatti; Roberto Floreanini; Stefano Olivares; Francesco Randi; Kelvin Titimbo; Marco Pividori; Fabio Novelli; Federico Cilento; Fulvio Parmigiani; Daniele Fausti

2014-02-19T23:59:59.000Z

166

Evaluation of Biomaterials Using Micro-Computerized Tomography  

SciTech Connect

Micro-computed tomography or Micro-CT is a high resolution, non-invasive, x-ray scanning technique that allows precise three-dimensional imaging and quantification of micro-architectural and structural parameters of objects. Tomographic reconstruction is based on a cone-beam convolution-back-projection algorithm. Micro-architectural and structural parameters such as porosity, surface area to volume ratio, interconnectivity, pore size, wall thickness, anisotropy and cross-section area of biomaterials and bio-specimens such as trabecular bone, polymer scaffold, bio-ceramics and dental restorative were evaluated through imaging and computer aided manipulation of the object scan data sets.

Torris, A. T. Arun; Columbus, K. C. Soumya; Saaj, U. S.; Krishnan, Kalliyana V. [Dental Products Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala-695012 (India); Nair, Manitha B. [Transmission Electron Microscopy Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala-695012 (India)

2008-09-26T23:59:59.000Z

167

BRAIN TUMOR VASCULAR NETWORK SEGMENTATION FROM MICRO-TOMOGRAPHY Xavier Descombes1  

E-Print Network (OSTI)

BRAIN TUMOR VASCULAR NETWORK SEGMENTATION FROM MICRO-TOMOGRAPHY Xavier Descombes1 , Franck for the systematic 3D analysis of supra- cellular structures such as micro-vascular networks [1, 2]. Since, France ABSTRACT Micro-tomography produces high resolution images of bio- logical structures

168

Investigating the stratigraphy of an alluvial aquifer using crosswell seismic traveltime tomography  

E-Print Network (OSTI)

can be used in situations where surface seismic reflection has failed e.g., Liberty et al., 1999Investigating the stratigraphy of an alluvial aquifer using crosswell seismic traveltime tomography In this study, we investigate the use of crosswell P-wave seismic tomography to obtain spatially extensive

Barrash, Warren

169

MAGNETIC RESONANCE ELECTRICAL IMPEDANCE TOMOGRAPHY (MR-EIT): A new technique for high resolution conductivity imaging  

E-Print Network (OSTI)

MAGNETIC RESONANCE ELECTRICAL IMPEDANCE TOMOGRAPHY (MR-EIT): A new technique for high resolution potentials and the magnetic fields produced by the probing current are measured. Surface potentials are measured by using conventional electrical impedance tomography techniques and high resolution magnetic

Eyüboðlu, Murat

170

Targeted Noninvasive Imaging of EGFR-Expressing Orthotopic Pancreatic Cancer Using Multispectral Optoacoustic Tomography  

Science Journals Connector (OSTI)

...11-13 ), and EGFR expression in breast, head and neck, and pancreatic cancer xenografts...opto-acoustic tomography (MSOT) of the brain and glioblastoma characterization.NeuroImage...concentration and oxygenation in the rat brain using high-resolution photoacoustic tomography...

Shanice V. Hudson; Justin S. Huang; Wenyuan Yin; Sabrin Albeituni; Jamie Rush; Anil Khanal; Jun Yan; Brian P. Ceresa; Hermann B. Frieboes; Lacey R. McNally

2014-11-01T23:59:59.000Z

171

Comparative study of microwave tomography segmentation techniques based on GMM and KNN in breast cancer detection  

Science Journals Connector (OSTI)

Microwave Tomography Imaging (MTI) is a new technology for early breast cancer detection. Compared to other methods such as X-ray, Magnetic Resonance Imaging (MRI) and ultrasound, the MTI technology is almost radiation-free, and low cost. However, the ... Keywords: gaussian mixture model, microwave tomography imaging, segmentation

Chunqiu Wang, Wei Wang, Sung Shin, Soon I. Jeon

2014-10-01T23:59:59.000Z

172

Cloud tomography: Role of constraints and a new algorithm Dong Huang,1  

E-Print Network (OSTI)

Cloud tomography: Role of constraints and a new algorithm Dong Huang,1 Yangang Liu,1 and Warren 2008. [1] Retrieving spatial distributions of cloud liquid water content from limited-angle emission data (passive microwave cloud tomography) is ill-posed, and a small inaccuracy in the data and

173

BLIND OCEAN ACOUSTIC TOMOGRAPHY: EXPERIMENTAL RESULTS ON THE INTIFANTE'00 DATA SET  

E-Print Network (OSTI)

BLIND OCEAN ACOUSTIC TOMOGRAPHY: EXPERIMENTAL RESULTS ON THE INTIFANTE'00 DATA SET S.M. Jesusa , C La Spezia, Italy. Summary: Blind Ocean Acoustic Tomography (BOAT) is an ocean remote exploration and depth can be used as focalizing parameters, together with the Bartlett power to indicate model fitness

Jesus, Sérgio M.

174

A neural network approach for image reconstruction in electron magnetic resonance tomography  

Science Journals Connector (OSTI)

An object-oriented, artificial neural network (ANN) based, application system for reconstruction of two-dimensional spatial images in electron magnetic resonance (EMR) tomography is presented. The standard back propagation algorithm is utilized to train ... Keywords: Artificial neural networks, Back propagation, Electron magnetic resonance tomography, Filtered back projection, Image reconstruction, Multiplicative algebraic reconstruction technique

D. Christopher Durairaj; Murali C. Krishna; Ramachandran Murugesan

2007-10-01T23:59:59.000Z

175

2-D TOMOGRAPHY FROM NOISY PROJECTIONS TAKEN AT UNKNOWN RANDOM DIRECTIONS  

E-Print Network (OSTI)

to the Fourier-projection slice theorem that relates the 1-D Fourier transform R(f) of the Radon transform2-D TOMOGRAPHY FROM NOISY PROJECTIONS TAKEN AT UNKNOWN RANDOM DIRECTIONS A. SINGER AND H.-T. WU Abstract. Computerized Tomography (CT) is a standard method for obtaining internal struc- ture of objects

Singer, Amit

176

STUDY OF TRANS-RECTAL NEAR-INFRARED DIFFUSE OPTICAL TOMOGRAPHY CONCURRENT  

E-Print Network (OSTI)

STUDY OF TRANS-RECTAL NEAR-INFRARED DIFFUSE OPTICAL TOMOGRAPHY CONCURRENT WITH TRANS of the requirements for the Degree of DOCTOR OF PHILOSOPHY May, 2010 #12;ii STUDY OF TRANS-RECTAL NEAR-INFRARED supported by the project Trans-rectal Near-Infrared Optical Tomography for Prostate Imaging from DOD

Piao, Daqing

177

1996 InternationalConference on Parallel Processing PARALLEL IMPLEMENTATION OF CONE BEAM TOMOGRAPHY  

E-Print Network (OSTI)

projections us- ing computed tomography (CT) is the noninvasive measure of structure from external as follows: A. Weight projection data B. Convolve weighted projection data Pe*(u,v) = P&L, U) * h(u) C1996 InternationalConference on Parallel Processing PARALLEL IMPLEMENTATION OF CONE BEAM TOMOGRAPHY

Chaudhary, Vipin

178

Spatially-Adaptive Reconstruction in Computed Tomography Based on Statistical Learning  

E-Print Network (OSTI)

, there exist techniques which require projections data only in the All authors are with the Computer Science1 Spatially-Adaptive Reconstruction in Computed Tomography Based on Statistical Learning Joseph a direct reconstruction algorithm for Computed Tomography, based on a local fusion of a few preliminary

Zibulevsky, Michael

179

Limited Angle Tomography of Sparse Images from Noisy Data using TLS MUSIC Algorithm  

E-Print Network (OSTI)

1 Limited Angle Tomography of Sparse Images from Noisy Data using TLS MUSIC Algorithm Andrew E The limited angle tomography problem is to recon- struct an image x(y, z) from its projections p(t, ) p-shaped region. This has applications to med- ical imaging and non-destructive evaluation where projection data

Yagle, Andrew E.

180

Saline tracer visualized with three-dimensional electrical resistivity tomography: Field-scale spatial moment analysis  

E-Print Network (OSTI)

Saline tracer visualized with three-dimensional electrical resistivity tomography: Field; accepted 14 February 2005; published 24 May 2005. [1] Cross-well electrical resistivity tomography (ERT., and S. M. Gorelick (2005), Saline tracer visualized with three-dimensional electrical resistivity

Singha, Kamini

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Doppler disc tomography applied to low mass AGN spin  

E-Print Network (OSTI)

Doppler tomography can provide a powerful means of determining black hole spin when our view to the central regions are revealed and obscured by optically thick orbiting material, and can provide an independent estimate that does not suffer as many degeneracies as traditional methods. For low mass AGN, time-dependent obscuration is expected to leave a signature in the changing spectrum of the disc emission which extends into the soft X-ray bandpass. We create a spectral model incorporating Doppler tomography and apply it to the case of the low mass (8$\\times$10$^{5}$ M$_{\\odot}$) AGN, RX J1301.9+2747 which shows unusual timing properties in the form of short-lived flares that we argue are best explained by the orbit of a window through an optically thick wind. Modelling the phase-resolved spectrum over the course of the highest data quality flare indicates a very low spin even when we relax our constraints. This is the lowest mass AGN for which a spin has been measured and the first via this technique. We not...

Middleton, Matthew

2014-01-01T23:59:59.000Z

182

A computed tomography implementation of multiple-image radiography  

SciTech Connect

Conventional x-ray computed tomography (CT) produces a single volumetric image that represents the spatially variant linear x-ray attenuation coefficient of an object. However, in many situations, differences in the x-ray attenuation properties of soft tissues are very small and difficult to measure in conventional x-ray imaging. In this work, we investigate an analyzer-based imaging method, called computed tomography multiple-image radiography (CT-MIR), which is a tomographic implementation of the recently proposed multiple-image radiography method. The CT-MIR method reconstructs concurrently three physical properties of the object. In addition to x-ray attenuation, CT-MIR produces volumetric images that represent the refraction and ultrasmall-angle scattering properties of the object. These three images can provide a rich description of the object's physical properties that are revealed by the probing x-ray beam. An imaging model for CT-MIR that is based on the x-ray transform of the object properties is established. The CT-MIR method is demonstrated by use of experimental data acquired at a synchroton radiation imaging beamline, and is compared to the pre-existing diffraction-enhanced imaging CT method. We also investigate the merit of an iterative reconstruction method for use with future clinical implementations of CT-MIR, which we anticipate would be photon limited.

Brankov, Jovan G.; Wernick, Miles N.; Yang Yongyi; Li Jun; Muehleman, Carol; Zhong Zhong; Anastasio, Mark A. [Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 and Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Rush University Medical Center, Chicago, Illinois 60616 (United States); National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States); Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 (United States)

2006-02-15T23:59:59.000Z

183

A continuation approach to regularization for traveltime tomography  

SciTech Connect

In most geometries in which seismic traveltime tomography is applied the slowness field is not well-determined from traveltimes alone. Nonuniqueness is common. Even when the slowness field is uniquely determined, small changes in the measured traveltimes can lead to large errors in the computed slowness field. A priori information is often available--well-logs, initial rough estimates of the slowness from structural geology, etc. This a priori information can be incorporated into a traveltime inversion algorithm using penalty terms. To further regularize the problem, smoothing constrains can also be incorporated using penalty terms by penalizing derivatives of the slowness field. A major decision to be made is the selection of the weights on the penalty terms, particularly the smoothing penalty weights. The authors use a continuation approach for selecting the smoothing penalty weights. Instead of fixing the smoothing penalty weights, they decrease the smoothing penalty weights in a step-by-step fashion, using the slowness model computed using the previous (larger) weights as the initial slowness model for the next step using the new (smaller) weights. A surprising outcome in synthetic problems is that the model error continues to decrease as they continue to decrease the smoothing penalty weights even after the data error had leveled off at the noise level. This continuation approach can solve synthetic problems more accurately than with fixed smoothing penalty weights, and appears to yield more features of interest in real-data applications of traveltime tomography.

Bube, K.P. [Univ. of Washington, Seattle, WA (United States); Langan, R.T. [Chevron Petroleum Technology, La Habra, CA (United States)

1994-12-31T23:59:59.000Z

184

Computed tomography of the thorax: a status report  

SciTech Connect

Computed tomography (CT) of the thorax shows early promise of important diagnostic advances. We believe that CT often provides information superior to that provided by standard roentgenographic techniques, is capable of significantly influencing patient management, and in selected instances, offers unique information not available by other methods. Computed tomography permits the imaging of mediastinal structures not possible with conventional roentgenographic methods and can diagnose with certainty benign mediastinal conditions such as pericardial cysts and focal or diffuse accumulations of fat. It is ideal for detecting pleural abnormalities and for displaying underlying parenchymal disease in patients with complex pleuroparenchymal shadows on conventional films. Pulmonary metastases unseen on the plain chest film can be detected with greater sensitivity than by any other method. Future applications of CT include the staging of mediastinal lymph nodes in bronchogenic carcinoma, the differentiation of benign from malignant solitary pulmonary nodules, and the detection of diffuse diseases involving the lung parenchyma before they are visible on conventional roentgenograms. Additional clinical experience and careful studies will determine CTs final role as a diagnostic aid for disorders of the thorax.

Pugatch, R.D.; Faling, L.J.

1981-11-01T23:59:59.000Z

185

Simultaneous CT and SPECT tomography using CZT detectors  

DOE Patents (OSTI)

A method for simultaneous transmission x-ray computed tomography (CT) and single photon emission tomography (SPECT) comprises the steps of: injecting a subject with a tracer compound tagged with a .gamma.-ray emitting nuclide; directing an x-ray source toward the subject; rotating the x-ray source around the subject; emitting x-rays during the rotating step; rotating a cadmium zinc telluride (CZT) two-sided detector on an opposite side of the subject from the source; simultaneously detecting the position and energy of each pulsed x-ray and each emitted .gamma.-ray captured by the CZT detector; recording data for each position and each energy of each the captured x-ray and .gamma.-ray; and, creating CT and SPECT images from the recorded data. The transmitted energy levels of the x-rays lower are biased lower than energy levels of the .gamma.-rays. The x-ray source is operated in a continuous mode. The method can be implemented at ambient temperatures.

Paulus, Michael J. (Knoxville, TN); Sari-Sarraf, Hamed (Lubbock, TX); Simpson, Michael L. (Knoxville, TN); Britton, Jr., Charles L. (Alcoa, TN)

2002-01-01T23:59:59.000Z

186

Reconstruction from a flexible number of projections in cone-beam computed tomography via active shape models  

E-Print Network (OSTI)

Reconstruction from a flexible number of projections in cone-beam computed tomography via active, and limited view computed tomography. 1. INTRODUCTION In recent years, cone beam computed tomography (CBCT a limited set of projections. Evaluations were performed using simulations with Shepp-Logan phantoms

Corso, Jason J.

187

Optical Coherence Tomography and Raman Spectroscopy of the retina  

SciTech Connect

Imaging the structure and correlating it with the biochemical content of the retina holds promise for fundamental research and for clinical applications. Optical coherence tomography (OCT) is commonly used to image the 3D structure of the retina and while the added functionality of biochemical analysis afforded by Raman scattering could provide critical molecular signatures for clinicians and researchers, there are many technical challenges to combining these imaging modalities. We present an ex vivo OCT microscope combined with Raman spectroscopy capable of collecting morphological and molecular information about a sample simultaneously. The combined instrument will be used to investigate remaining technical challenges to combine these imaging modalities, such as the laser power levels needed to achieve a Raman signal above the noise level without damaging the sample.

Evans, J W; Zawadzki, R J; Liu, R; Chan, J; Lane, S; Werner, J S

2009-01-16T23:59:59.000Z

188

3D Jet Tomography of the Twisted Color Glass Condensate  

E-Print Network (OSTI)

Jet Tomography is proposed as a new test of Color Glass Condensate (CGC) initial conditions in non-central $A+A$ collisions. The $k_{T}$ factorized CGC formalism is used to calculate the rapidity twist in the reaction plane of both the bulk low $p_T 6$ GeV partons. Unlike conventional perturbative QCD, the initial high $p_{T}$ CGC gluons are shown to be twisted even further away from the beam axis than the the low $p_T$ bulk at high rapidities $|\\eta|>2$. Differential directed flow $v_{1}(p_{T}>6,|\\eta|>2)$ is proposed to test this novel high $p_T$ rapidity twist predicted by the CGC model.

A. Adil; M. Gyulassy; T. Hirano

2005-09-23T23:59:59.000Z

189

Electrical resistance tomography from measurements inside a steel cased borehole  

DOE Patents (OSTI)

Electrical resistance tomography (ERT) produced from measurements taken inside a steel cased borehole. A tomographic inversion of electrical resistance measurements made within a steel casing was then made for the purpose of imaging the electrical resistivity distribution in the formation remotely from the borehole. The ERT method involves combining electrical resistance measurements made inside a steel casing of a borehole to determine the electrical resistivity in the formation adjacent to the borehole; and the inversion of electrical resistance measurements made from a borehole not cased with an electrically conducting casing to determine the electrical resistivity distribution remotely from a borehole. It has been demonstrated that by using these combined techniques, highly accurate current injection and voltage measurements, made at appropriate points within the casing, can be tomographically inverted to yield useful information outside the borehole casing.

Daily, William D. (Livermore, CA); Schenkel, Clifford (Walnut Creek, CA); Ramirez, Abelardo L. (Pleasanton, CA)

2000-01-01T23:59:59.000Z

190

Iterative methods for dose reduction and image enhancement in tomography  

DOE Patents (OSTI)

A system and method for creating a three dimensional cross sectional image of an object by the reconstruction of its projections that have been iteratively refined through modification in object space and Fourier space is disclosed. The invention provides systems and methods for use with any tomographic imaging system that reconstructs an object from its projections. In one embodiment, the invention presents a method to eliminate interpolations present in conventional tomography. The method has been experimentally shown to provide higher resolution and improved image quality parameters over existing approaches. A primary benefit of the method is radiation dose reduction since the invention can produce an image of a desired quality with a fewer number projections than seen with conventional methods.

Miao, Jianwei; Fahimian, Benjamin Pooya

2012-09-18T23:59:59.000Z

191

Temporoparietal cortex in aphasia. Evidence from positron emission tomography  

SciTech Connect

Forty-four aphasic patients were examined with (F18)-fluorodeoxyglucose positron emission tomography in a resting state to determine whether consistent glucose metabolic abnormalities were present. Ninety-seven percent of subjects showed metabolic abnormalities in the angular gyrus, 89% in the supramarginal gyrus, and 87% in the lateral and transverse superior temporal gyrus. Pearson product moment correlations were calculated between regional metabolic measures and performance on the Western Aphasia Battery. No significant correlations were found between the Western Aphasia Battery scores and right hemisphere metabolic measures. Most left hemisphere regions correlated with more than one score from the Western Aphasia Battery. Temporal but not frontal regions had significant correlations to the comprehension score. The left temporoparietal region was consistently affected in these subjects, suggesting that common features in the aphasias were caused by left temporoparietal dysfunction, while behavioral differences resulted from (1) the extent of temporoparietal changes, and (2) dysfunction elsewhere in the brain, particularly the left frontal and subcortical areas.

Metter, E.J.; Hanson, W.R.; Jackson, C.A.; Kempler, D.; van Lancker, D.; Mazziotta, J.C.; Phelps, M.E. (National Institute of Aging, Baltimore, MD (USA))

1990-11-01T23:59:59.000Z

192

Thermal stability of curved ray tomography for corrosion monitoring  

SciTech Connect

Guided wave tomography is being developed as an effective tool for continuous monitoring of corrosion and erosion depth in pipelines. A pair of transmit- and receive-ring arrays of ultrasonic transducers encircles the pipe and delimits the section to be monitored. In curved ray tomography (CRT), the depth profile is estimated from the time delay matrix, ??, whose ij-th entry is the phase traveltime difference between the current and baseline signals measured between transducers i and j of the transmit and receive-ring arrays, respectively. Under perfectly stable experimental conditions, the non-zero entries of ?? are only due to the occurrence of damage and provide a reliable input to CRT. However, during field operation, ?? can develop non-zero entries due to a number of environmental changes ranging from temperature variations to degradation of transducer-pipe coupling and transducer intrinsic performance. Here, we demonstrate that these sources of instability can be eliminated by exploiting the spatial diversity of array measurements in conjunction with EMAT transducer technology which is intrinsically stable owing to its non-contact nature. The study is based on a full-scale experiment performed on a schedule 40, 8’ diameter, 3 m length steel pipe, monitored with two EMAT ring arrays. It is shown that for an irregularly shaped defect the proposed method yields maximum depth estimations that are as accurate as single point ultrasonic thickness gaging measurements and over a wide temperature range up to 175°C. The results indicate that advanced inversion schemes in combination with EMAT transduction offer great potential for continuously monitoring the progression of corrosion or erosion damage in the oil and gas industry.

Willey, C. L. [Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, OH 45221 (United States); Simonetti, F.; Nagy, P. B. [Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, OH 45221,USA and Cincinnati NDE, Cincinnati, OH 45244 (United States); Instanes, G. [ClampOn AS, 5162 Laksevaag, Bergen, Norway and Cincinnati NDE, Cincinnati, OH 45244 (United States)

2014-02-18T23:59:59.000Z

193

Reconstruction algorithm for limited-angle diffraction tomography for microwave NDE  

SciTech Connect

Microwave tomography is becoming a popular imaging modality in nondestructive evaluation and medicine. A commonly encountered challenge in tomography in general is that in many practical situations a full 360° angular access is not possible and with limited access, the quality of reconstructed image is compromised. This paper presents an approach for reconstruction with limited angular access in diffraction tomography. The algorithm takes advantage of redundancies in image Fourier space data obtained from diffracted field measurements and couples it to an error minimization technique using a constrained total variation (CTV) minimization. Initial results from simulated data have been presented here to validate the approach.

Paladhi, P. Roy; Klaser, J.; Tayebi, A.; Udpa, L.; Udpa, S. [Non-destructive Evaluation Lab, Dept. of Electrical and Computer Engineering, College of Engineering, Michigan State University, Lansing, MI 48824-1226 (United States)

2014-02-18T23:59:59.000Z

194

ARM - Field Campaign - Ground-based Cloud Tomography Experiment at SGP  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsGround-based Cloud Tomography Experiment at SGP govCampaignsGround-based Cloud Tomography Experiment at SGP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Ground-based Cloud Tomography Experiment at SGP 2009.05.26 - 2009.07.17 Lead Scientist : Dong Huang For data sets, see below. Description Knowledge of 3D cloud properties is pressingly needed in many research fields. One of the problems encountered when trying to represent 3D cloud fields in numerical models is that the existing techniques cannot provide necessary observations at the required spatial scale and resolution. We tested a new promising technique for measuring 3D cloud microphysical structure, called cloud microwave tomography, at the Southern Great Plains (SGP) site for one month in late April 2009. Five microwave scanning

195

Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance  

NLE Websites -- All DOE Office Websites (Extended Search)

Non-medical Uses of Computed Tomography (CT) Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) Resources with Additional Information Computed Tomography (CT) Scanner CT Scanner - Courtesy Stanford University Department of Energy Resources Engineering Computed tomography (CT) and Nuclear Magnetic Resonance (NMR) have been used to resolve industrial problems, for materials characterizations, and to provide non-destructive evaluations for discovering flaws in parts before their use, resulting in greater reliability and greater safety for workers; to identify the presence and facilitate the recovery/extraction of oil, water, coal, and/or gas; and to provide non-destructive testing and quality control of fresh fruits and vegetables, enhancing the safety of food. These benefits of non-medical uses of CT and NMR contribute to the economy and improve people's lives.

196

Predicting Breast Tumor Response to Neoadjuvant Chemotherapy with Diffuse Optical Spectroscopic Tomography prior to Treatment  

Science Journals Connector (OSTI)

...Imaging Predicting Breast Tumor Response to Neoadjuvant Chemotherapy with Diffuse Optical Spectroscopic Tomography prior to Treatment Shudong Jiang 1 * Brian W. Pogue...Medicine, Hanover, New Hampshire. Purpose: To determine whether pretreatment biomarkers...

Shudong Jiang; Brian W. Pogue; Peter A. Kaufman; Jiang Gui; Michael Jermyn; Tracy E. Frazee; Steven P. Poplack; Roberta DiFlorio-Alexander; Wendy A. Wells; Keith D. Paulsen

2014-12-01T23:59:59.000Z

197

Imaging the Soultz Enhanced Geothermal Reservoir using double-difference tomography and microseismic data  

E-Print Network (OSTI)

We applied the double-difference tomography method to image the P and S-wave velocity structure of the European Hot Dry Rock geothermal reservoir (also known as the Soultz Enhanced Geothermal System) at Soultz-sous-Forets, ...

Piñeros Concha, Diego Alvaro

2010-01-01T23:59:59.000Z

198

Tiny endoscopic optical coherence tomography probe driven by a miniaturized hollow ultrasonic motor  

E-Print Network (OSTI)

We present an endoscopic probe for optical coherence tomography (OCT) equipped with a miniaturized hollow ultrasonic motor that rotates the objective lens and provides an internal channel for the fiber to pass through, ...

Chen, Tianyuan

199

Method for Quantitative Study of Airway Functional Microanatomy Using Micro-Optical Coherence Tomography  

E-Print Network (OSTI)

We demonstrate the use of a high resolution form of optical coherence tomography, termed micro-OCT (?OCT), for investigating the functional microanatomy of airway epithelia. ?OCT captures several key parameters governing ...

Diephuis, Bradford J.

200

High-resolution three-dimensional optical coherence tomography imaging of kidney microanatomy ex vivo  

E-Print Network (OSTI)

Optical coherence tomography (OCT) is an emerging medical imaging technology that enables high-resolution, noninvasive, cross-sectional imaging of microstructure in biological tissues in situ and in real time. When combined ...

Chen, Yu

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Visualizing Plant Development and Gene Expression in Three Dimensions Using Optical Projection Tomography  

Science Journals Connector (OSTI)

...Projection Tomography Group, Medical Research Council Human Genetics...Edinburgh Mouse Atlas Group, Medical Research Council Human Genetics...Human Genetics Unit of the Medical Research Council (Edinburgh...1989), and per-voxel lighting (Ebert and Rheingans, 2001...

Karen Lee; Jerome Avondo; Harris Morrison; Lilian Blot; Margaret Stark; James Sharpe; Andrew Bangham; Enrico Coen

2006-08-11T23:59:59.000Z

202

Ambient noise tomography for wavespeed and anisotropy in the crust of southwestern China  

E-Print Network (OSTI)

The primary objective of this thesis is to improve our understanding of the crustal structure and deformation in the southeastern Tibetan Plateau and adjacent regions using surface wave tomography. Green's functions for ...

Huang, Hui, Ph. D. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

203

P- and S- wave tomography of the crust and uppermost mantle in China and surrounding areas  

E-Print Network (OSTI)

This thesis involves inverting the seismic structure of the crust and uppermost mantle in China from the P- and S-wave travel-time tomography. The main contributions of this research are: 1) introducing the adaptive moving ...

Sun, Youshun, 1970-

2005-01-01T23:59:59.000Z

204

Computed tomography in congenital hip dislocation. The role of acetabular anteversion  

SciTech Connect

Computed tomography usually can provide accurate documentation of the adequacy of a reduction in congenital dislocation of the hip. It should supplement other radiographic examinations when the status of a reduction is in question because the patient is wearing a plaster cast. The computed tomography scan provides a clear image of the reduction in the transverse plane, so that anterior or posterior subluxation of the femoral head can be easily detected. In addition it allows direct measurement of acetabular anteversion which previously had not been possible with non-invasive studies in the living patient. Radiation exposure is less than that for conventional tomography. We used computed tomography in five patients with congenital dislocation of the hip and our study provided new evidence concerning the role of acetabular anteversion in this condition. Acetabular anteversion was increased on the dislocated side in each patient, and returned to normal as treatment progressed.

Browning, W.H.; Rosenkrantz, H.; Tarquinio, T.

1982-01-01T23:59:59.000Z

205

NEURAL NETWORKS FOR DISCRETE TOMOGRAPHY K.J. Batenburg a W.A. Kosters b  

E-Print Network (OSTI)

NEURAL NETWORKS FOR DISCRETE TOMOGRAPHY K.J. Batenburg a W.A. Kosters b a Mathematical Institute of crystalline solids at atomic resolution from electron microscopic images can be considered the ``holy grail

Kosters, Walter

206

A Full Field Inversion Method for Acoustic Tomography of Ocean Currents  

Science Journals Connector (OSTI)

An extension of the matched field inversion technique to include oceanic current tomography is considered. Matching of the non-reciprocity of acoustic fields propagated in opposite directions (instead of match...

O. A. Godin; D. Yu. Mikhin; A. V. Mokhov

1995-01-01T23:59:59.000Z

207

Review paper Seismic interferometry and ambient noise tomography in the British Isles  

E-Print Network (OSTI)

Review paper Seismic interferometry and ambient noise tomography in the British Isles Heather. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 2. Theory and method of seismic interferometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 4.2. Seismic interferometry across the Scottish Highlands

208

Piezoelectric transducer based miniature catheter for ultrahigh speed endoscopic optical coherence tomography  

E-Print Network (OSTI)

We developed a piezoelectric transducer (PZT) based miniature catheter with an outer diameter of 3 mm for ultrahigh speed endoscopic optical coherence tomography (OCT) using Fourier domain modelocked (FDML) laser at a 480 ...

Tsai, Tsung-Han

209

Evolution of upper mantle beneath East Asia and the Tibetan Plateau from P-wave tomography  

E-Print Network (OSTI)

The main objective of the research presented in this thesis is to improve our understanding for the evolution of the upper mantle beneath East Asia and the Tibetan Plateau through high resolution P-wave tomography. The ...

Li, Chang, Ph.D.

2007-01-01T23:59:59.000Z

210

Toward whole-body optical imaging of rats using single-photon counting fluorescence tomography  

Science Journals Connector (OSTI)

We used single-photon counting (SPC) detection for diffuse fluorescence tomography to image nanomolar (nM) concentrations of reporter dyes through a rat. Detailed phantom data are...

Leblond, Frederic; Tichauer, Kenneth M; Holt, Robert W; El-Ghussein, Fadi; Pogue, Brian W

2011-01-01T23:59:59.000Z

211

Diffraction and coherence in breast ultrasound tomography: a study with a toroidal array  

SciTech Connect

Ultrasound is commonly used as an adjunct to mammography for diagnostic evaluation of suspicions arising from breast cancer screening. As an alternative to conventional sonography that uses hand-held transducers, toroidal array probes that encircle the breast immersed in a water bath have been investigated for ultrasound tomography. In this paper, two sets of experiments performed with a prototype ultrasound scanner on a phantom and a human breast in vivo are used to investigate the effects of diffraction and coherence in ultrasound tomography. Reconstructions obtained with transmission diffraction tomography (TDT) are compared with conventional reflection imaging and computerized ultrasound tomography showing a substantial improvement. The in vivo tests demonstrate that TDT can image the complex boundary of a cancer mass and suggest that it can reveal the anatomy of milk ducts and Cooper's ligaments.

Huang, Lianjie [Los Alamos National Laboratory; Simonetti, Francesco [IMPERIAL COLL.; Duric, Neb [KCI; Littrup, Peter [KCI

2008-01-01T23:59:59.000Z

212

Optical coherence tomography based on intensity correlations of quasi-thermal light  

E-Print Network (OSTI)

We show theoretically that the longitudinal resolution of conventional optical coherence tomography can be improved by a factor of radic2 when a two-photon (as opposed to a single-photon) sensitive detector is used, and ...

Zerom, Petros

213

in vivo Photothermal Optical Coherence Tomography of Targeted Mouse Brain Tumors using Gold Nanostars  

Science Journals Connector (OSTI)

We present structural and molecular-contrast imaging of mouse brain tumors using photo-thermal optical coherence tomography (PT-OCT) in vivo. Based on strong PT response of gold...

Heo, Jung; Jang, Eunji; Haam, Seungjoo; Oh, Seung Jae; Huh, Yong-Min; Suh, Jin-Suck; Chung, Euiheon; Joo, Chulmin

214

Digital signal processing techniques for optical coherence tomography : OCT and OCT image enhancement  

E-Print Network (OSTI)

Digital signal processing (DSP) techniques were developed to improve the flexibility, functionality, and image quality of ultrahigh resolution optical coherence tomography (OCT) systems. To reduce the dependence of OCT ...

Adler, Desmond Christopher, 1978-

2004-01-01T23:59:59.000Z

215

A microwave tomography system using a tunable mirror for beam steering  

SciTech Connect

Microwave tomography is a fast-growing technique in the fields of NDE and medical industry. This paper presents a new microwave tomography system which reduces the complexities of conventional microwave imaging systems by utilizing a reconfigurable mirror, a tunable reflectarray antenna. In order to build a tunable reflectarray with beam steering capabilities, the unit cell characteristics should dynamically alter. Modelling and experimental results of a single unit cell are presented in this work.

Tayebi, A. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physic (United States); Tang, J. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Paladhi, P. Roy; Udpa, L.; Udpa, S. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

2014-02-18T23:59:59.000Z

216

Geophysical muon imaging: feasibility and limits  

Science Journals Connector (OSTI)

......Gaussian with mean N and standard deviation N. However...interval is obtained through standard procedure and we have...made very constructive reviews of a former version of...2010. Muon tomography: plans for observations in the...measurements with application in mining geophysics, Geophysics......

N. Lesparre; D. Gibert; J. Marteau; Y. Déclais; D. Carbone; E. Galichet

2010-12-01T23:59:59.000Z

217

Quantum process tomography of unitary and near-unitary maps  

E-Print Network (OSTI)

We study quantum process tomography given the prior information that the map is a unitary or close to a unitary process. We show that a unitary map on a $d$-level system is completely characterized by a minimal set of $d^2{+}d$ elements associated with a collection of POVMs, in contrast to the $d^4{-}d^2$ elements required for a general completely positive trace-preserving map. To achieve this lower bound, one must probe the map with a particular set of $d$ pure states. We further compare the performance of different compressed sensing algorithms used to reconstruct a near-unitary process from such data. We find that when we have accurate prior information, an appropriate compressed sensing method reduces the required data needed for high-fidelity estimation, and different estimators applied to the same data are sensitive to different types of noise. Compressed sensing techniques can therefore be used both as indicators of error models and to validate the use of the prior assumptions.

Charles H. Baldwin; Amir Kalev; Ivan H. Deutsch

2014-04-22T23:59:59.000Z

218

Nanoscale Cluster Detection in Massive Atom Probe Tomography Data  

SciTech Connect

Recent technological advances in atom probe tomography (APT) have led to unprecedented data acquisition capabilities that routinely generate data sets containing hundreds of millions of atoms. Detecting nanoscale clusters of different atom types present in these enormous amounts of data and analyzing their spatial correlations with one another are fundamental to understanding the structural properties of the material from which the data is derived. Extant algorithms for nanoscale cluster detection do not scale to large data sets. Here, a scalable, CUDA-based implementation of an autocorrelation algorithm is presented. It isolates spatial correlations amongst atomic clusters present in massive APT data sets in linear time using a linear amount of storage. Correctness of the algorithm is demonstrated using large synthetically generated data with known spatial distributions. Benefits and limitations of using GPU-acceleration for autocorrelation-based APT data analyses are presented with supporting performance results on data sets with up to billions of atoms. To our knowledge, this is the first nanoscale cluster detection algorithm that scales to massive APT data sets and executes on commodity hardware.

Seal, Sudip K [ORNL] [ORNL; Yoginath, Srikanth B [ORNL] [ORNL; Miller, Michael K [ORNL] [ORNL

2014-01-01T23:59:59.000Z

219

Measurement strategy for rectangular electrical capacitance tomography sensor  

Science Journals Connector (OSTI)

To investigate the influence of the measurement strategy for the rectangular electrical capacitance tomography (ECT) sensor a Finite Element Method (FEM) is utilized to create the model for simulation. The simulation was carried out using COMSOL Multiphysics{trade mark serif} and Matlab{trade mark serif}. The length-width ratio of the rectangular sensing area is 5. Twelve electrodes are evenly arranged surrounding the pipe. The covering ratio of the electrodes is 90%. The capacitances between different electrode pairs are calculated for a bar distribution. The air of the relative permittivity 1.0 and the material of the permittivity 3.0 are used for the calibration. The relative permittivity of the second phase is 3.0. The noise free and noise data are used for the image reconstruction using the Linear Back Projection (LBP). The measurement strategies with 1- 2- and 4- electrode excitation are compared using the correlation coefficient. Preliminary results show that the measurement strategy with 2-electrode excitation outperforms other measurement strategies with 1- or 4-electrode excitation.

Jiamin Ye

2014-01-01T23:59:59.000Z

220

Compressed sensing quantum process tomography for superconducting quantum gates  

E-Print Network (OSTI)

We apply the method of compressed sensing (CS) quantum process tomography (QPT) to characterize quantum gates based on superconducting Xmon and phase qubits. Using experimental data for a two-qubit controlled-Z gate, we obtain an estimate for the process matrix $\\chi$ with reasonably high fidelity compared to full QPT, but using a significantly reduced set of initial states and measurement configurations. We show that the CS method still works when the amount of used data is so small that the standard QPT would have an underdetermined system of equations. We also apply the CS method to the analysis of the three-qubit Toffoli gate with numerically added noise, and similarly show that the method works well for a substantially reduced set of data. For the CS calculations we use two different bases in which the process matrix $\\chi$ is approximately sparse, and show that the resulting estimates of the process matrices match each ther with reasonably high fidelity. For both two-qubit and three-qubit gates, we characterize the quantum process by not only its process matrix and fidelity, but also by the corresponding standard deviation, defined via variation of the state fidelity for different initial states.

Andrey V. Rodionov; Andrzej Veitia; R. Barends; J. Kelly; Daniel Sank; J. Wenner; John M. Martinis; Robert L. Kosut; Alexander N. Korotkov

2014-07-03T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Measurement strategy for rectangular electrical capacitance tomography sensor  

SciTech Connect

To investigate the influence of the measurement strategy for the rectangular electrical capacitance tomography (ECT) sensor, a Finite Element Method (FEM) is utilized to create the model for simulation. The simulation was carried out using COMSOL Multiphysics(trade mark, serif) and Matlab(trade mark, serif). The length-width ratio of the rectangular sensing area is 5. Twelve electrodes are evenly arranged surrounding the pipe. The covering ratio of the electrodes is 90%. The capacitances between different electrode pairs are calculated for a bar distribution. The air of the relative permittivity 1.0 and the material of the permittivity 3.0 are used for the calibration. The relative permittivity of the second phase is 3.0. The noise free and noise data are used for the image reconstruction using the Linear Back Projection (LBP). The measurement strategies with 1-, 2- and 4- electrode excitation are compared using the correlation coefficient. Preliminary results show that the measurement strategy with 2-electrode excitation outperforms other measurement strategies with 1- or 4-electrode excitation.

Ye, Jiamin; Ge, Ruihuan; Qiu, Guizhi; Wang, Haigang [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing, 100190 (China)

2014-04-11T23:59:59.000Z

222

Dark energy and matter evolution from lensing tomography  

Science Journals Connector (OSTI)

Reconstructed from lensing tomography, the evolution of the dark matter density field in the well-understood linear regime can provide model-independent constraints on the growth function of structure and the evolution of the dark energy density. We examine this potential in the context that high-redshift cosmology has in the future been fixed by cosmic microwave background measurements. We construct sharp tests for the existence of multiple dark matter components or a dark energy component that is not a cosmological constant. These functional constraints can be transformed into physically motivated model parameters. From the growth function, the fraction of the dark matter in a smooth component, such as a light neutrino, may be constrained to a statistical precision of ?(f)?0.0006fsky-1/2 by a survey covering a fraction of sky fsky with a redshift resolution ?z=0.1. For the dark energy, a parametrization in terms of the present energy density ?DE, equation of state w, and its redshift derivative w?, the constraints correspond to ?(w)=0.009fsky-1/2 and a degenerate combination of the other two parameters. For a fixed ?DE, ?(w?)=0.046fsky-1/2.

Wayne Hu

2002-10-30T23:59:59.000Z

223

Electrical resistance tomography using steel cased boreholes as electrodes  

DOE Patents (OSTI)

An electrical resistance tomography method is described which uses steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constrain the models. 2 figs.

Daily, W.D.; Ramirez, A.L.

1999-06-22T23:59:59.000Z

224

Electrical resistance tomography using steel cased boreholes as electrodes  

DOE Patents (OSTI)

An electrical resistance tomography method using steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constain the models.

Daily, William D. (Livermore, CA); Ramirez, Abelardo L. (Pleasanton, CA)

1999-01-01T23:59:59.000Z

225

Temperature Tomography of the Soft X-Ray Corona: Measurements  

Science Journals Connector (OSTI)

We analyze long-exposure and off-pointing Yohkoh/SXT data of the solar corona observed on 1992 August 26. We develop a new (temperature) tomography method that is based on a forward-fitting method of a four-parameter model to the observed soft X-ray fluxes F1(h) and F2(h) of two SXT wavelength filters as a function of height h. The model is defined in terms of a differential emission measure (DEM) distribution dEM(h, T)/dT, which includes also a temperature dependence of density scale heights ?n(T) = q??T and allows us to quantify deviations (q? ? 1) from hydrostatic equilibrium (q? = 1). This parametrization facilitates a proper line-of-sight integration and relates the widely used filter ratio temperature TFR to the peak of the DEM distribution. A direct consequence of the multi-scale height atmosphere is that the filter ratio temperature TFR(h) is predicted to increase with height, even if all magnetic field lines are isothermal. Our model fitting reveals that coronal holes and quiet-Sun regions are in perfect hydrostatic equilibrium but that coronal streamers have a scale height that exceeds the hydrostatic scale height by a factor of up to q? 2.3, which underscores the dynamic nature of coronal streamers. Our density measurements in coronal holes are slightly lower than most of the white-light polarized brightness inversions and seem to come closer to the requirements of solar wind models. Our DEM model provides also a physical framework for the semiempirical Baumbach-Allen formula and quantifies the temperature ranges and degree of hydrostaticity of the K, L, and F coronae.

Markus J. Aschwanden; Loren W. Acton

2001-01-01T23:59:59.000Z

226

X-ray Computed Tomography of coal: Final report  

SciTech Connect

X-ray Computed Tomography (CT) is a method of mapping with x-rays the internal structures of coal. The technique normally produces 2-D images of the internal structures of an object. These images can be recast to create pseudo 3-D representations. CT of coal has been explored for a variety of different applications to coal and coal processing technology. In a comparison of CT data with conventional coal analyses and petrography, CT was found to offer a good indication of the total ash content of the coal. The spatial distribution of the coal mineral matter as seen with CT has been suggested as an indicator of coal washability. Studies of gas flow through coal using xenon gas as a tracer have shown the extremely complicated nature of the modes of penetration of gas through coal, with significant differences in the rates at which the gas can pass along and across the bedding planes of coal. In a special furnace designed to allow CT images to be taken while the coal was being heated, the pyrolysis and gasification of coal have been studied. Gasification rates with steam and CO/sub 2/ for a range of coal ranks have been obtained, and the location of the gasification reactions within the piece of coal can be seen. Coal drying and the progress of the pyrolysis wave into coal have been examined when the coal was subjected to the kind of sudden temperature jump that it might experience in fixed bed gasifier applications. CT has also been used to examine stable flow structures within model fluidized beds and the accessibility of lump coal to microbial desulfurization. 53 refs., 242 figs., 26 tabs.

Maylotte, D.H.; Spiro, C.L.; Kosky, P.G.; Lamby, E.J.

1986-12-01T23:59:59.000Z

227

Prior-based artifact correction (PBAC) in computed tomography  

SciTech Connect

Purpose: Image quality in computed tomography (CT) often suffers from artifacts which may reduce the diagnostic value of the image. In many cases, these artifacts result from missing or corrupt regions in the projection data, e.g., in the case of metal, truncation, and limited angle artifacts. The authors propose a generalized correction method for different kinds of artifacts resulting from missing or corrupt data by making use of available prior knowledge to perform data completion. Methods: The proposed prior-based artifact correction (PBAC) method requires prior knowledge in form of a planning CT of the same patient or in form of a CT scan of a different patient showing the same body region. In both cases, the prior image is registered to the patient image using a deformable transformation. The registered prior is forward projected and data completion of the patient projections is performed using smooth sinogram inpainting. The obtained projection data are used to reconstruct the corrected image. Results: The authors investigate metal and truncation artifacts in patient data sets acquired with a clinical CT and limited angle artifacts in an anthropomorphic head phantom data set acquired with a gantry-based flat detector CT device. In all cases, the corrected images obtained by PBAC are nearly artifact-free. Compared to conventional correction methods, PBAC achieves better artifact suppression while preserving the patient-specific anatomy at the same time. Further, the authors show that prominent anatomical details in the prior image seem to have only minor impact on the correction result. Conclusions: The results show that PBAC has the potential to effectively correct for metal, truncation, and limited angle artifacts if adequate prior data are available. Since the proposed method makes use of a generalized algorithm, PBAC may also be applicable to other artifacts resulting from missing or corrupt data.

Heußer, Thorsten, E-mail: thorsten.heusser@dkfz-heidelberg.de; Brehm, Marcus [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)] [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Ritschl, Ludwig [Ziehm Imaging GmbH, Donaustraße 31, 90451 Nürnberg (Germany)] [Ziehm Imaging GmbH, Donaustraße 31, 90451 Nürnberg (Germany); Sawall, Stefan; Kachelrieß, Marc [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, Friedrich–Alexander–University (FAU) of Erlangen–Nürnberg, Henkestraße 91, 91052 Erlangen (Germany)] [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, Friedrich–Alexander–University (FAU) of Erlangen–Nürnberg, Henkestraße 91, 91052 Erlangen (Germany)

2014-02-15T23:59:59.000Z

228

Patient preferences and acceptable risk for computed tomography in trauma  

Science Journals Connector (OSTI)

AbstractBackground Rising use of computed tomography (CT) to evaluate patients with trauma has increased both patient costs and risk of cancer from ionizing radiation, without demonstrable improvements in outcome. Patient-centred care mandates disclosure of the potential risks, costs and benefits of diagnostic testing whenever possible. Objective We sought to determine (1) patient preferences regarding emergency department (ED) real-time discussions of risks and costs of CT during their trauma evaluations; and (2) whether varying levels of odds of detection of life-threatening injury (LTI) were associated with changes in patient preferences for CT. Methods Excluding patients already receiving CT and patients with altered mental status, we surveyed adult, English-speaking patients at four Level I verified trauma centres. After informing subjects of cancer risks associated with chest CT, we used hypothetical scenarios with varying \\{LTIs\\} to assess patients’ preferences regarding CT. Results Of 941 patients enrolled, 50% were male and their mean age was 42 years. Most patients stated they would prefer to discuss CT radiation risks (73.5%, 95% CI [66.1–80.8]) and costs (53.2%, 95% CI [46.1–60.4]) with physicians. As the odds of detecting LTI decreased, preferences for receiving CT decreased accordingly: LTI 25% (desire 91.2%, 95% CI [89.4–93.1]), LTI 10% (desire 79.3%, 95% CI [76.7–81.9]), LTI 5% (desire 69.1%, 95% CI [66.1–72.1]) and LTI risks and costs of CT prior to receiving imaging. As the odds of detecting LTI decrease, fewer patients prefer to have CT; at an LTI threshold of 2%, approximately half of patients would prefer to forego CT. Adding out-of-pocket costs reduced this proportion to one-third of patients.

Robert M. Rodriguez; Tarann M. Henderson; Anne M. Ritchie; Mark I. Langdorf; Ali S. Raja; Eric Silverman; Joelle Schlang; Bryan Sloane; Clare E. Ronan; Craig L. Anderson; Brigitte M. Baumann

2014-01-01T23:59:59.000Z

229

Time-dependent seismic tomography and its application to the Coso  

Open Energy Info (EERE)

and its application to the Coso and its application to the Coso geothermal area, 1996-2006 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Time-dependent seismic tomography and its application to the Coso geothermal area, 1996-2006 Details Activities (1) Areas (1) Regions (0) Abstract: Measurements of temporal changes in Earth structure are commonly determined using local earthquake tomography computer programs that invert multiple seismic-wave arrival time data sets separately and assume that any differences in the structural results arise from real temporal variations. This assumption is dangerous because the results of repeated tomography experiments would differ even if the structure did not change, simply because of variation in the seismic ray distribution caused by the natural

230

Time-Dependent Seismic Tomography of the Coso Geothermal Area, 1996-2004 |  

Open Energy Info (EERE)

Dependent Seismic Tomography of the Coso Geothermal Area, 1996-2004 Dependent Seismic Tomography of the Coso Geothermal Area, 1996-2004 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Time-dependent seismic tomography of the Coso geothermal area, 1996-2004 Details Activities (1) Areas (1) Regions (0) Abstract: Local-earthquake tomographic images were calculated for each of the years 1996 - 2004 using arrival times from the U.S. Navy's permanent seismometer network at the Coso geothermal area, California. The results show irregular strengthening with time of the wave-speed ratio VP/VS at shallow depths. These changes result predominately from progressive relative increase in VS with respect to VP, and could result from processes associated with geothermal operations such as decrease in fluid pressure

231

Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance  

Office of Scientific and Technical Information (OSTI)

Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) Resources with Additional Information Computed Tomography (CT) Scanner CT Scanner - Courtesy Stanford University Department of Energy Resources Engineering Computed tomography (CT) and Nuclear Magnetic Resonance (NMR) have been used to resolve industrial problems, for materials characterizations, and to provide non-destructive evaluations for discovering flaws in parts before their use, resulting in greater reliability and greater safety for workers; to identify the presence and facilitate the recovery/extraction of oil, water, coal, and/or gas; and to provide non-destructive testing and quality control of fresh fruits and vegetables, enhancing the safety of food. These benefits of non-medical uses of CT and NMR contribute to the economy and improve people's lives.

232

3rd World Congress on Industrial Process Tomography, Banff, Canada Non Iterative Inversion Method for Electrical Resistance,  

E-Print Network (OSTI)

Method for Electrical Resistance, Capacitance and Inductance Tomography for Two Phase Materials materials. For ERT, we assume as measured data the (dc) resistance matrix between electrodes in contact resistance tomography (ERT) is used to reconstruct the conductivity distribution inside a material. The ERT

Lionheart, Bill

233

>18F-labeled BPA positron emmision tomography (PET) based Boron Neutron Capture Therapy on malignant glioma patients in Japan  

Science Journals Connector (OSTI)

...Development, Sep 12-15, 2006 18F-labeled BPA positron emmision tomography (PET) based...borocaptate (BSH) and boronophenylalanine (BPA), both of which have been used clinically...at Osaka Medical College.18F-labeled BPA positron emmision tomography (BPA-PET...

Shinji Kawabata; Shin-Ichi Miyatake; Minoru Miyashita; Atsushi Doi; Kyouko Iida; Toshihiko Kuroiwa; Yoshio Imahori; Koji Ono

2006-10-01T23:59:59.000Z

234

F Labeling of a Near-Infrared Fluorophore Enables Positron Emission Tomography and Optical Imaging of Sentinel Lymph Nodes  

E-Print Network (OSTI)

Fast 18 F Labeling of a Near-Infrared Fluorophore Enables Positron Emission Tomography and Optical- with a near-infrared fluorophore into a single molecule. Attachment to targeting ligands enables localization by positron emission tomography (PET) and near-infrared fluorescence (NIRF). Our first application

Tsien, Roger Y.

235

Cone-beam mammo-computed tomography from data along two tilting arcs Hengyong Yu,b  

E-Print Network (OSTI)

Cone-beam mammo-computed tomography from data along two tilting arcs Kai Zeng,a Hengyong Yu . To address this problem, x-ray tomosynthesis and cone-beam computed tomography CT are two compelling from a limited num- ber of projections.4 Since its introduction in 1972, the area of tomosynthesis has

Virginia Tech

236

An overview of fast convergent ordered-subsets reconstruction methods for emission tomography based on the incremental EM  

E-Print Network (OSTI)

. Introduction In emission tomography, the reconstruction of vast quantities of noisy, low-count data in prac [4]. Statistical reconstruction is useful in emission computed tomography due to its ability to ac by using only a subset of the projection data per sub-iteration. The OSEM algorithm is fast, parallelizable

Rangarajan, Anand

237

Accounting for spatially variable resolution in electrical resistivity tomography through field-scale rock-physics relations  

E-Print Network (OSTI)

Accounting for spatially variable resolution in electrical resistivity tomography through field of the voltages measured in an electrical resistivity tomography ERT survey produces maps of electrical resistivity, which can be used to infer changes in electrical properties, such as those caused

Singha, Kamini

238

ECG-GATED C-ARM COMPUTED TOMOGRAPHY USING L1 REGULARIZATION Cyril Mory 1,3  

E-Print Network (OSTI)

ECG-GATED C-ARM COMPUTED TOMOGRAPHY USING L1 REGULARIZATION Cyril Mory 1,3 , Bo Zhang 3 , Vincent of the algorithm used for the minimization. Index Terms -- C-Arm, computed tomography, ECG- gating, augmented arises from the synchronization with the patient's electrocardiogram (ECG), which is necessary to avoid

Paris-Sud XI, Université de

239

Multi-Resolution Seismic Tomography Based on Recursive Tessellation Hierarchy  

SciTech Connect

A 3-D global tomographic model that reconstructs velocity structure at multiple scales and incorporates laterally variable seismic discontinuities is currently being developed. The model parameterization is node-based where nodes are placed along vertices defined by triangular tessellations of a spheroidal surface. The triangular tessellation framework is hierarchical. Starting with a tetrahexahedron representing the whole globe (1st level of the hierarchy, 24 faces), they divide each triangle of the tessellation into daughter triangles. The collection of all daughter triangles comprises the 2nd level of the tessellation hierarchy and further recursion produces an arbitrary number of tessellation levels and arbitrarily fine node-spacing. They have developed an inversion procedure that takes advantage of the recursive properties of the tessellation hierarchies by progressively solving for shorter wavelength heterogeneities. In this procedure, we first perform the tomographic inversion using a tessellation level with coarse node spacing. They find that a coarse node spacing of approximately 8{sup o} is adequate to capture bulk regional properties. They then conduct the tomographic inversion on a 4{sup o} tessellation level using the residuals and inversion results from the 8{sup o} run. In practice they find that the progressive tomography approach is robust, providing an intrinsic regularization for inversion stability and avoids the issue of predefining resolution levels. Further, determining average regional properties with coarser tessellation levels enables long-wavelength heterogeneities to account for sparsely sampled regions (or regions of the mantle where longer wavelength patterns of heterogeneity suffice) while allowing shorter length-scale heterogeneities to emerge where necessary. They demonstrate the inversion approach with a set of synthetic test cases that mimic the complex nature of data arrangements (mixed-determined inversion) common to most tomographic problems. They also apply the progressive inversion approach with Pn waves traveling within the Middle East region and compare the results to simple tomographic inversions. As expected from synthetic testing, the progressive approach results in detailed structure where there is high data density and broader regional anomalies where seismic information is sparse. The ultimate goal is to use these methods to produce a seamless, multi-resolution global tomographic model with local model resolution determined by the constraints afforded by available data. They envisage this new technique as the general approach to be employed for future multi-resolution model development with complex arrangements of regional and teleseismic information.

Simmons, N A; Myers, S C; Ramirez, A

2009-07-01T23:59:59.000Z

240

Improved proton computed tomography by dual modality image reconstruction  

SciTech Connect

Purpose: Proton computed tomography (CT) is a promising image modality for improving the stopping power estimates and dose calculations for particle therapy. However, the finite range of about 33 cm of water of most commercial proton therapy systems limits the sites that can be scanned from a full 360° rotation. In this paper the authors propose a method to overcome the problem using a dual modality reconstruction (DMR) combining the proton data with a cone-beam x-ray prior. Methods: A Catphan 600 phantom was scanned using a cone beam x-ray CT scanner. A digital replica of the phantom was created in the Monte Carlo code Geant4 and a 360° proton CT scan was simulated, storing the entrance and exit position and momentum vector of every proton. Proton CT images were reconstructed using a varying number of angles from the scan. The proton CT images were reconstructed using a constrained nonlinear conjugate gradient algorithm, minimizing total variation and the x-ray CT prior while remaining consistent with the proton projection data. The proton histories were reconstructed along curved cubic-spline paths. Results: The spatial resolution of the cone beam CT prior was retained for the fully sampled case and the 90° interval case, with the MTF = 0.5 (modulation transfer function) ranging from 5.22 to 5.65?linepairs/cm. In the 45° interval case, the MTF = 0.5 dropped to 3.91?linepairs/cm For the fully sampled DMR, the maximal root mean square (RMS) error was 0.006 in units of relative stopping power. For the limited angle cases the maximal RMS error was 0.18, an almost five-fold improvement over the cone beam CT estimate. Conclusions: Dual modality reconstruction yields the high spatial resolution of cone beam x-ray CT while maintaining the improved stopping power estimation of proton CT. In the case of limited angles, the use of prior image proton CT greatly improves the resolution and stopping power estimate, but does not fully achieve the quality of a 360° proton CT scan.

Hansen, David C., E-mail: dch@ki.au.dk; Bassler, Niels [Experimental Clinical Oncology, Aarhus University, 8000 Aarhus C (Denmark)] [Experimental Clinical Oncology, Aarhus University, 8000 Aarhus C (Denmark); Petersen, Jørgen Breede Baltzer [Medical Physics, Aarhus University Hospital, 8000 Aarhus C (Denmark)] [Medical Physics, Aarhus University Hospital, 8000 Aarhus C (Denmark); Sørensen, Thomas Sangild [Computer Science, Aarhus University, 8000 Aarhus C, Denmark and Clinical Medicine, Aarhus University, 8200 Aarhus N (Denmark)] [Computer Science, Aarhus University, 8000 Aarhus C, Denmark and Clinical Medicine, Aarhus University, 8200 Aarhus N (Denmark)

2014-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


241

Characterizing properties of fractured porous media using x-ray computed tomography  

E-Print Network (OSTI)

CHARACTERIZING PROPERTIES OF FRACTURED POROUS MEDIA USING X-RAY COMPUTED TOMOGRAPHY A Thesis by JAMES MUDRA IV Submitted to the O f f i c e of Graduate Studies of Texas A&M University- p a r t i a l f u l f i l l m e n t of the requirements f... or the degree of MASTER OF SCIENCE December 1990 Major Subject: Chemical Engineering CHARACTERIZING PROPERTIES OF FRACTURED POROUS MEDIA USING X-RAY COMPUTED TOMOGRAPHY A Thesis by JAMES MUDRA IV Approved as to s t y l e and content by: (Member) (Head...

Mudra, James

2012-06-07T23:59:59.000Z

242

A novel synthetic aperture technique for breast tomography with toroidal arrays  

SciTech Connect

Ultrasound is commonly used as an adjunct to mammography for diagnostic evaluation of suspicions arising from breast cancer screening. As an alternative to conventional sonography that uses hand-held transducers, toroidal array probes that encircle the breast immersed in a water bath have been investigated for ultrasound tomography. This paper introduces a new method for three-dimensional synthetic aperture diffraction tomography that maximizes the resolution in the scanning direction and provides quantitative reconstructions of the acoustic properties of the object. The method is validated by means of numerical simulations.

Huang, Lianjie [Los Alamos National Laboratory; Simonetti, Francesco [IMPERIAL COLLEGE

2009-01-01T23:59:59.000Z

243

Current status of patient radiation doses from computed tomography examinations in Tanzania  

Science Journals Connector (OSTI)

......from computed tomography examinations in Tanzania J. E. Ngaile 1 P. Msaki 1 R. Kazema...P.O. Box 35063, Dar es Salaam, Tanzania 2 Department of Radiology, Muhimbili...P.O. Box 65001, Dar es Salaam, Tanzania The aim of this study was to assess the......

J. E. Ngaile; P. Msaki; R. Kazema

2006-12-01T23:59:59.000Z

244

THE VALUE OF BOREHOLE -TO-SURFACE INFORMATION IN NEAR-SURFACE CROSSWELL SEISMIC TOMOGRAPHY  

E-Print Network (OSTI)

seismic reflection cannot (e.g. Liberty et al., 1999; Musil et al., 2002). The images producedTHE VALUE OF BOREHOLE -TO-SURFACE INFORMATION IN NEAR-SURFACE CROSSWELL SEISMIC TOMOGRAPHY Geoff J properties is important in many fields. One method that can image the seismic velocity structure

Barrash, Warren

245

Joint microseismic location and anisotropic tomography using differential arrival times and differential backazimuths  

Science Journals Connector (OSTI)

......with simultaneous anisotropic tomography, using...hydraulic fracturing in shale gas/oil play...monitoring of the shale gas/oil production...any heterogeneous anisotropic medium, the derivatives...In some cases, shale gas/oil drilling...moduli Cij and the anisotropic parameters is required......

Junlun Li; Haijiang Zhang; William L. Rodi; M. Nafi Toksoz

2013-01-01T23:59:59.000Z

246

Roadmap: Radiologic Imaging Sciences -Computed Tomography (with certification and ATS Radiologic Technology) -  

E-Print Network (OSTI)

Roadmap: Radiologic Imaging Sciences - Computed Tomography (with certification and ATS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-CTHA] Regional College Catalog Year: 2013-2014 Page 1 of 2 | Last Updated: 30-Apr-13/LNHD This roadmap is a recommended semester

Sheridan, Scott

247

Roadmap: Radiologic Imaging Sciences -Computed Tomography (with certification and ATS Radiologic Technology) -  

E-Print Network (OSTI)

Roadmap: Radiologic Imaging Sciences - Computed Tomography (with certification and ATS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-CTHA] Regional College Catalog Year: 2012-2013 Page 1 of 2 | Last Updated: 25-Oct-12/LNHD This roadmap is a recommended semester

Sheridan, Scott

248

Group-velocity tomography of South America and the surrounding oceans  

E-Print Network (OSTI)

Group-velocity tomography of South America and the surrounding oceans Oleg Vdovin,1 Jose¨ A. Rial,2 propagating across South America and the surrounding oceans. Broad-band waveform data from about 765 events and show that the average resolution across South America is about 60^80 for Rayleigh waves and 70

Ritzwolle, Mike

249

Surface-to-tunnel seismic tomography studies at Yucca Mountain, Nevada  

E-Print Network (OSTI)

Surface-to-tunnel seismic tomography studies at Yucca Mountain, Nevada Roland Gritto, Valeri A in the proposed nuclear waste repository area at Yucca Mountain, Nevada. A 5-km-long source line and a 3-km-long receiver line were located on top of Yucca Mountain ridge and inside the Exploratory Study Facility (ESF

Korneev, Valeri A.

250

VIDEO IDENTIFICATION USING VIDEO TOMOGRAPHY Gustavo Leon, Hari Kalva, and Borko Furht  

E-Print Network (OSTI)

VIDEO IDENTIFICATION USING VIDEO TOMOGRAPHY Gustavo Leon, Hari Kalva, and Borko Furht Department of Computer Science and Engineering, Florida Atlantic University, Boca Raton, FL, USA ABSTRACT Video popularity of online video services. The problem addressed in this paper is the identification of a given

Kalva, Hari

251

Quantum process tomography of single photon quantum channels with controllable decoherence  

E-Print Network (OSTI)

We characterized unital quantum channels of single photon polarization qubits. The channels are composed of two birefringent crystals and wave-plates, where their decoherence properties are controlled. An experimental comparison between two different depolarizing configurations was performed using a quantum process tomography procedure. The results are with a high fidelity to the theoretical predictions.

A. Shaham; H. S. Eisenberg

2011-08-07T23:59:59.000Z

252

Cross gender-age trabecular texture analysis in cone beam computed tomography  

E-Print Network (OSTI)

only! #12;2 6-Professor and Director. Division of Oral and Maxillofacial Radiology, Temple University osteoporosis screening tools in the jaws. Keywords: cone-beam computed tomography, osteoporosis, radiology osteoporosis prescreening method is through the analysis of dental imaging data, which is collected during

Ling, Haibin

253

Transport-and diffusion-based optical tomography in small domains: a comparative study  

E-Print Network (OSTI)

reconstructions based on the radiative transport and diffusion equations in optical tomography for media of small that the propaga- tion of near-infrared light in tissues is best modeled by the radiative transport equation (RTE the transport equation by its diffusion approximation, which models the spa- tial density of photons

Bal, Guillaume

254

T. J. Brukilacchio, Ph.D. Thesis 2003 Review of Diffuse Optical Tomography  

E-Print Network (OSTI)

to the radiative transport equation. Analytical models have been developed for simple geometries Optical Tomography The diffusion approximation to the radiative transport equation is the most widely used extensively studied in atmospheric physics, and in neutron transport [1,2]. The radiative transfer equation

255

Three-dimensional optical tomography with the equation of radiative transfer  

E-Print Network (OSTI)

on a transport-backtransport method applied to the two-dimensional time-dependent equation of radiative transferThree-dimensional optical tomography with the equation of radiative transfer Gassan S. Abdoulaev reconstruction scheme that is based on the time-independent equation of radiative transfer (ERT) and allows

Hielscher, Andreas

256

Geophys. J. Int. () , 1?? Cross-section electrical resistance tomography of La Soufri`ere of  

E-Print Network (OSTI)

to unconsolidated material saturated by hydrothermal fluids. Two of them are associated with partial flank collapses. Key words: Electrical properties ­ tomography ­ image processing ­ Volcanic hazards and risks 1 in the hydrothermal reservoirs and produces episodic chlorine spikes in the Carbet hot spring located on the north

Adler, Andy

257

Time-lapse electrical resistivity tomography applied to cave sustainability (Barbados) and groundwater exploration (Saint Lucia)  

E-Print Network (OSTI)

In this work we apply the method of two-dimensional time-lapse electrical resistivity tomography (2D time-lapse ERT) for two different problems. In the first problem, we monitor the structural stability of the roof of the ...

Agramakova, Yulia

2011-01-01T23:59:59.000Z

258

Enhanced renal image contrast by ethanol fixation in phase-contrast X-ray computed tomography  

Science Journals Connector (OSTI)

To obtain higher image contrast in phase-contrast X-ray computed tomography, the fixation technique has been examined with 100% ethanol and the commonly used 10% formalin. Fine renal structure was depicted by the ethanol fixation, and the image was approximately three times higher in contrast in all renal areas due to the physical properties and strong dehydration by ethanol.

Shirai, R.

2014-06-12T23:59:59.000Z

259

Laboratory sandbox validation of transient hydraulic tomography W. A. Illman,1,3  

E-Print Network (OSTI)

by geostatistical methods which require numerous measurements. This requires the drilling of numerous boreholes) as well as large-scale (unidirectional flow-through tests) estimates of hydraulic parameters. Results show as large-scale hydraulic parameter data. In addition, we find that the transient hydraulic tomography

Daniels, Jeffrey J.

260

An Exact Modeling of Signal Statistics in Energy-integrating X-ray Computed Tomography  

E-Print Network (OSTI)

assumption was made that the number of x-ray quanta within an energy interval in the spectrum followsAn Exact Modeling of Signal Statistics in Energy-integrating X-ray Computed Tomography Yi Fan1 School of Medicine, Atlanta, GA 30322 ABSTRACT Energy-integrating detection of x-ray sources is widely

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Detecting Perched Water Bodies Using Surface-seismic Time-lapse Traveltime Tomography  

E-Print Network (OSTI)

Chapter 25 Detecting Perched Water Bodies Using Surface-seismic Time-lapse Traveltime Tomography remediation. Previous near-surface geophysical time-lapse studies have focused on electrical or electromagnetic (EM) techniques (including ground-penetrating radar) or borehole methods. To evaluate the utility

Hubbard, Susan

262

Computerized Tomography and its Applications: a Guided Tour \\Lambda J.B.T.M. Roerdink  

E-Print Network (OSTI)

of the Radon transform and related transforms, inversion formulas, uniqueness, ill­posedness and stability: Computerized tomography, Radon transform, inversion formulas, recon­ struction algorithms, ill­posed problems projections', i.e. the recovery of a function from its line or (hyper)plane integrals (from the Greek ø ' o

Roerdink, Jos B.T.M.

263

Radiation dose reduction and image enhancement in biological imaging through equally-sloped tomography  

E-Print Network (OSTI)

Iterative reconstruction algorithm Radiation dose reduction Image enhancement Computed tomography a b s t r-dose data acquisi- tion schemes have made it possible to record multiple projections quickly without-energy electrons (Henderson, 1995), which limits the number of projections that can be acquired. Furthermore

Miao, Jianwei "John"

264

Image Reconstruction for Positron Emission Tomography Using Fuzzy Nonlinear Anisotropic Diffusion Penalty  

E-Print Network (OSTI)

with a limited number of data appears as a highly underdetermined ill-posed problem. The projection data computed tomography. However, such algorithms are sensitive to noise artifacts so that the reconstruction projections that are close to the measured projection data. Iterative based ML reconstruction algorithms

Paris-Sud XI, Université de

265

Bayesian Image Reconstruction for Transmission Tomography Using Mixture Model Priors and Deterministic Annealing  

E-Print Network (OSTI)

degradations in emission computed tomography (ECT) for both PET and SPECT. To improve quantitative accuracy transmission projection data. However, the transmission projection data is itself usually very noisy due to the necessities of a short-time acquisition and limited count rate . The low-count data makes the reconstruction

266

Line-source based X-ray Tomography Deepak Bharkhada1,2  

E-Print Network (OSTI)

resolution is limited by the time necessary to acquire sufficient projection data over an angular range. #12 Science, Wake Forest University, Winston-Salem, NC 27109 Abstract: Current computed tomography (CT reconstruction technique (SART) algorithm for image reconstruction from projection data generated by an x

Plemmons, Robert J.

267

An Efficient Approach for Optical Radiative Transfer Tomography using the Spherical Harmonics Discrete Ordinates Method  

E-Print Network (OSTI)

This paper introduces a method to preform optical tomography, using 3D radiative transfer as the forward model. We use an iterative approach predicated on the Spherical Harmonics Discrete Ordinates Method (SHDOM) to solve the optimization problem in a scalable manner. We illustrate with an application in remote sensing of a cloudy atmosphere.

Levis, Aviad; Aides, Amit; Davis, Anthony B

2015-01-01T23:59:59.000Z

268

Degradation of Li/S Battery Electrodes Studied Using X-ray Phase Contrast Tomography  

E-Print Network (OSTI)

the Li-ion battery market. This can be explained by their high energy density, high operating voltage1 Degradation of Li/S Battery Electrodes Studied Using X-ray Phase Contrast Tomography L. Zielkea. Zengerlea,f and S. Thielea,g Lithium/sulphur batteries are promising candidates for future energy storage

Schmidt, Volker

269

Soft X-ray tomography of phenotypic switching and the cellular response to antifungal peptoids  

E-Print Network (OSTI)

Soft X-ray tomography of phenotypic switching and the cellular response to antifungal peptoids that circumvent fungal drug- resistance mechanisms. In this work we used soft X-ray tomogra- phy to image of an entire, fully functional biological system, i.e., in the milieu of a cell (8, 10). Recently, soft X-ray

Barron, Annelise E.

270

Multiscale imaging of human thyroid pathologies using integrated Optical Coherence Tomography (OCT) and Optical Coherence Microscopy (OCM)  

E-Print Network (OSTI)

We evaluate the feasibility of optical coherence tomography (OCT) and optical coherence microscopy (OCM) for imaging of benign and malignant thyroid lesions ex vivo using intrinsic optical contrast. Thirty four thyroid ...

Zhou, Chao

271

Simultaneous maximum-likelihood reconstruction for x-ray grating based phase-contrast tomography avoiding intermediate phase retrieval  

E-Print Network (OSTI)

Phase-wrapping artifacts, statistical image noise and the need for a minimum amount of phase steps per projection limit the practicability of x-ray grating based phase-contrast tomography, when using filtered back projection reconstruction. For conventional x-ray computed tomography, the use of statistical iterative reconstruction algorithms has successfully reduced artifacts and statistical issues. In this work, an iterative reconstruction method for grating based phase-contrast tomography is presented. The method avoids the intermediate retrieval of absorption, differential phase and dark field projections. It directly reconstructs tomographic cross sections from phase stepping projections by the use of a forward projecting imaging model and an appropriate likelihood function. The likelihood function is then maximized with an iterative algorithm. The presented method is tested with tomographic data obtained through a wave field simulation of grating based phase-contrast tomography. The reconstruction result...

Ritter, André; Durst, Jürgen; Gödel, Karl; Haas, Wilhelm; Michel, Thilo; Rieger, Jens; Weber, Thomas; Wucherer, Lukas; Anton, Gisela

2013-01-01T23:59:59.000Z

272

Neutron Computed Tomography of Freeze/thaw Phenomena in Polymer Electrolyte Fuel Cells  

SciTech Connect

This report summarizes the final year's progress of the three-year NEER program. The overall objectives of this program were to 1) design and construct a sophisticated hight-resolution neutron computed tomography (NCT) facility, 2) develop novel and sophisticated liquid water and ice quantification analysis software for computed tomography, and 3) apply the advanced software and NCT capability to study liquid and ice distribution in polymer electrolyte fuel cells (PEFCs) under cold-start conditions. These objectives have been accomplished by the research team, enabling a new capability for advanced 3D image quantification with neutron imaging for fuel cell and other applications. The NCT water quantification methodology and software will greatly add to the capabilities of the neutron imaging community, and the quantified liquid water and ice distribution provided by its application to PEFCs will enhance understanding and guide design in the fuel cell community.

Matthew M. Mech; Jack Brenizer; Kenan Unlu; A.K. Heller

2008-12-12T23:59:59.000Z

273

Retrieving the 3D matter power spectrum and galaxy biasing parameters from lensing tomography  

E-Print Network (OSTI)

With the availability of galaxy distance indicators in weak lensing surveys, lensing tomography can basically be harnessed to constrain the spatial 3D matter power spectrum over a range in redshift and physical scale. Furthermore, by adding galaxy-galaxy lensing and galaxy clustering this can be extended to probe the 3D galaxy-matter and galaxy-galaxy power spectrum or, alternatively, galaxy biasing parameters. To achieve this aim, this paper introduces and discusses minimum variance estimators and a more general Bayesian approach to statistically invert a set of noisy tomography 2-point correlation functions, measured within a confined opening angle. Both methods are constructed such that they probe deviations of the 3D power spectrum from a fiducial power spectrum. Thereby a direct comparison of theory and data is achieved, the physical scale and redshift of deviations can in principle be identified. By devising a new Monte Carlo technique the measurement noise in the correlators is quantified for a fiducia...

Simon, Patrick

2012-01-01T23:59:59.000Z

274

Vacuum photodiode detectors for soft x-ray ITER plasma tomography  

SciTech Connect

A special type of vacuum photodiode detector (VPD) for x-ray tomography of (ITER) plasma is described. Laboratory experiments demonstrate that VPD has high sensitivity to thermal x-rays and low sensitivity to hard gamma rays and neutrons. It was shown that in ITER environment the signal due to thermal x-rays will surpass the background signal by more than a factor of 100.

Gott, Yu.V.; Stepanenko, M.M. [RRC, Nuclear Fusion Institute, Kurchatov sq.1, Moscow, 123182 (Russian Federation)

2005-07-15T23:59:59.000Z

275

Barium Titanate Nanoparticles as Exogenous Contrast Agents in Second Harmonic Optical Coherence Tomography  

E-Print Network (OSTI)

fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Chair of Committee, Brian Applegate Committee Members, Kristen Maitland Jim Ji Head of Department, Gerard Cote May 2013 Major Subject: Biomedical Engineering...-OCT without producing inferior reflector artifacts. 38 REFERENCES Applegate, Brian. (2004). Polarization-resolved Second-harmonic-generation Optical Coherence Tomography in Collagen. Optics Letters, 29(19), 2252-2254. H?usler G., Lindner M. W...

Pearson, Jeremy T

2013-05-06T23:59:59.000Z

276

Improved fluorescence-enhanced optical imaging and tomography by enhanced excitation light rejection  

E-Print Network (OSTI)

) .................................................................88 xvi NOMENCLATURE Abbreviations 2-D Two-dimension 3-D Three-dimension ACR Amplitude ratio AOI Angle of incidence CCD Charge coupled device CT Computed tomography CW... molecular markers of disease at pico-molar to nano-molar concentrations. Light in the UV-visible range does not enable deep 7 penetration for fluorescence imaging mainly because of autofluorescence and a high level of endogenous absorbers...

Hwang, Kil Dong

2009-05-15T23:59:59.000Z

277

A simple setup for neutron tomography at the Portuguese Nuclear Research Reactor  

E-Print Network (OSTI)

A simple setup for neutron radiography and tomography was recently installed at the Portuguese Research Reactor. The objective of this work was to determine the operational characteristics of the installed setup, namely the irradiation time to obtain the best dynamic range for individual images and the spatial resolution. The performance of the equipment was demonstrated by imaging a fragment of a 17th century decorative tile.

M. A. Stanojev Pereira; J. G. Marques; R. Pugliesi

2012-05-15T23:59:59.000Z

278

Application of computed tomography to enhanced oil recovery studies in naturally fractured reservoirs  

E-Print Network (OSTI)

formations of the Middle East (Dukhan field in Qatar, the Jasjid-I-Sulamain, Kirkuk field and Haft- Kel fields in Iran) was made by Birks . Oil recoveries were mathematically determined as a function of time and saturations, for different fracture lengths...APPLICATION OF COMPUTED TOMOGRAPHY TO ENHANCED OIL RECOVERY STUDIES IN NATURALLY FRACTURED RESERVOIRS A Thesis by JAMES MARK FINEOUT Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

Fineout, James Mark

2012-06-07T23:59:59.000Z

279

3D and 4D magnetic susceptibility tomography based on complex MR images  

DOE Patents (OSTI)

Magnetic susceptibility is the physical property for T2*-weighted magnetic resonance imaging (T2*MRI). The invention relates to methods for reconstructing an internal distribution (3D map) of magnetic susceptibility values, .chi. (x,y,z), of an object, from 3D T2*MRI phase images, by using Computed Inverse Magnetic Resonance Imaging (CIMRI) tomography. The CIMRI technique solves the inverse problem of the 3D convolution by executing a 3D Total Variation (TV) regularized iterative convolution scheme, using a split Bregman iteration algorithm. The reconstruction of .chi. (x,y,z) can be designed for low-pass, band-pass, and high-pass features by using a convolution kernel that is modified from the standard dipole kernel. Multiple reconstructions can be implemented in parallel, and averaging the reconstructions can suppress noise. 4D dynamic magnetic susceptibility tomography can be implemented by reconstructing a 3D susceptibility volume from a 3D phase volume by performing 3D CIMRI magnetic susceptibility tomography at each snapshot time.

Chen, Zikuan; Calhoun, Vince D

2014-11-11T23:59:59.000Z

280

VECTOR TOMOGRAPHY FOR THE CORONAL MAGNETIC FIELD. II. HANLE EFFECT MEASUREMENTS  

SciTech Connect

In this paper, we investigate the feasibility of saturated coronal Hanle effect vector tomography or the application of vector tomographic inversion techniques to reconstruct the three-dimensional magnetic field configuration of the solar corona using linear polarization measurements of coronal emission lines. We applied Hanle effect vector tomographic inversion to artificial data produced from analytical coronal magnetic field models with equatorial and meridional currents and global coronal magnetic field models constructed by extrapolation of real photospheric magnetic field measurements. We tested tomographic inversion with only Stokes Q, U, electron density, and temperature inputs to simulate observations over large limb distances where the Stokes I parameters are difficult to obtain with ground-based coronagraphs. We synthesized the coronal linear polarization maps by inputting realistic noise appropriate for ground-based observations over a period of two weeks into the inversion algorithm. We found that our Hanle effect vector tomographic inversion can partially recover the coronal field with a poloidal field configuration, but that it is insensitive to a corona with a toroidal field. This result demonstrates that Hanle effect vector tomography is an effective tool for studying the solar corona and that it is complementary to Zeeman effect vector tomography for the reconstruction of the coronal magnetic field.

Kramar, M. [Physics Department, The Catholic University of America, 620 Michigan Avenue NE, Washington, DC 20064 (United States); Inhester, B. [Max-Planck-Institut fuer Sonnensystemforschung, Max-Plank-Str. 2, D-37191 Katlenburg-Lindau (Germany); Lin, H. [Institute for Astronomy, University of Hawaii at Manoa, 34 Ohia Ku Street, Pukalani, Maui, HI 96768 (United States); Davila, J., E-mail: maxim.i.kramar@nasa.gov, E-mail: Joseph.M.Davila@nasa.gov, E-mail: inhester@mps.mpg.de, E-mail: lin@ifa.hawaii.edu [NASA-GSFC, Code 671, Greenbelt, MD 20771 (United States)

2013-09-20T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Robust inverse scattering full waveform seismic tomography for imaging complex structure  

SciTech Connect

Seismic tomography becomes important tool recently for imaging complex subsurface. It is well known that imaging complex rich fault zone is difficult. In this paper, The application of time domain inverse scattering wave tomography to image the complex fault zone would be shown on this paper, especially an efficient time domain inverse scattering tomography and their run in cluster parallel computer which has been developed. This algorithm is purely based on scattering theory through solving Lippmann Schwienger integral by using Born's approximation. In this paper, it is shown the robustness of this algorithm especially in avoiding the inversion trapped in local minimum to reach global minimum. A large data are solved by windowing and blocking technique of memory as well as computation. Parameter of windowing computation is based on shot gather's aperture. This windowing technique reduces memory as well as computation significantly. This parallel algorithm is done by means cluster system of 120 processors from 20 nodes of AMD Phenom II. Benchmarking of this algorithm is done by means Marmoussi model which can be representative of complex rich fault area. It is shown that the proposed method can image clearly the rich fault and complex zone in Marmoussi model even though the initial model is quite far from the true model. Therefore, this method can be as one of solution to image the very complex mode.

Nurhandoko, Bagus Endar B.; Sukmana, Indriani; Wibowo, Satryo; Deny, Agus; Kurniadi, Rizal; Widowati, Sri; Mubarok, Syahrul; Susilowati; Kaswandhi [Wave Inversion and Subsurface Fluid Imaging Research (WISFIR) Lab., Complex System Research Division, Physics Department, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung. and Rock Fluid Imaging Lab., Rock Physics and Cluster C (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung (Indonesia); Physics Department of Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung, Indonesia and Institut Teknologi Telkom, Bandung (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung (Indonesia)

2012-06-20T23:59:59.000Z

282

Structural and optical properties of wood and wood finishes studied using optical coherence tomography: application to an 18th century Italian violin  

Science Journals Connector (OSTI)

Optical coherence tomography (OCT) is especially attractive for the study of cultural heritage artifacts because it is noninvasive and nondestructive. We have developed an original...

Latour, Gaël; Echard, Jean-Philippe; Soulier, Balthazar; Emond, Isabelle; Vaiedelich, Stéphane; Elias, Mady

2009-01-01T23:59:59.000Z

283

Positron Emission Tomography/Computed Tomography Imaging of Residual Skull Base Chordoma Before Radiotherapy Using Fluoromisonidazole and Fluorodeoxyglucose: Potential Consequences for Dose Painting  

SciTech Connect

Purpose: To detect the presence of hypoxic tissue, which is known to increase the radioresistant phenotype, by its uptake of fluoromisonidazole (18F) (FMISO) using hybrid positron emission tomography/computed tomography (PET/CT) imaging, and to compare it with the glucose-avid tumor tissue imaged with fluorodeoxyglucose (18F) (FDG), in residual postsurgical skull base chordoma scheduled for radiotherapy. Patients and Methods: Seven patients with incompletely resected skull base chordomas were planned for high-dose radiotherapy (dose {>=}70 Gy). All 7 patients underwent FDG and FMISO PET/CT. Images were analyzed qualitatively by visual examination and semiquantitatively by computing the ratio of the maximal standardized uptake value (SUVmax) of the tumor and cerebellum (T/C R), with delineation of lesions on conventional imaging. Results: Of the eight lesion sites imaged with FDG PET/CT, only one was visible, whereas seven of nine lesions were visible on FMISO PET/CT. The median SUVmax in the tumor area was 2.8 g/mL (minimum 2.1; maximum 3.5) for FDG and 0.83 g/mL (minimum 0.3; maximum 1.2) for FMISO. The T/C R values ranged between 0.30 and 0.63 for FDG (median, 0.41) and between 0.75 and 2.20 for FMISO (median,1.59). FMISO T/C R >1 in six lesions suggested the presence of hypoxic tissue. There was no correlation between FMISO and FDG uptake in individual chordomas (r = 0.18, p = 0.7). Conclusion: FMISO PET/CT enables imaging of the hypoxic component in residual chordomas. In the future, it could help to better define boosted volumes for irradiation and to overcome the radioresistance of these lesions. No relationship was founded between hypoxia and glucose metabolism in these tumors after initial surgery.

Mammar, Hamid, E-mail: hamid.mammar@unice.fr [Radiation Oncology Department, Antoine Lacassagne Center, Nice (France) [Radiation Oncology Department, Antoine Lacassagne Center, Nice (France); CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France); Kerrou, Khaldoun; Nataf, Valerie [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)] [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France); Pontvert, Dominique [Proton Therapy Center of Orsay, Curie Institute, Paris (France)] [Proton Therapy Center of Orsay, Curie Institute, Paris (France); Clemenceau, Stephane [Department of Neurosurgery, Pitie-Salpetriere Hospital, Paris (France)] [Department of Neurosurgery, Pitie-Salpetriere Hospital, Paris (France); Lot, Guillaume [Department of Neurosurgery, Adolph De Rothschild Foundation, Paris (France)] [Department of Neurosurgery, Adolph De Rothschild Foundation, Paris (France); George, Bernard [Department of Neurosurgery, Lariboisiere Hospital, Paris (France)] [Department of Neurosurgery, Lariboisiere Hospital, Paris (France); Polivka, Marc [Department of Pathology, Lariboisiere Hospital, Paris (France)] [Department of Pathology, Lariboisiere Hospital, Paris (France); Mokhtari, Karima [Department of Pathology, Pitie-Salpetriere Hospital, Paris (France)] [Department of Pathology, Pitie-Salpetriere Hospital, Paris (France); Ferrand, Regis; Feuvret, Loiec; Habrand, Jean-louis [Proton Therapy Center of Orsay, Curie Institute, Paris (France)] [Proton Therapy Center of Orsay, Curie Institute, Paris (France); Pouyssegur, Jacques; Mazure, Nathalie [CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France)] [CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France); Talbot, Jean-Noeel [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)] [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)

2012-11-01T23:59:59.000Z

284

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

285

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

286

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

287

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Wednesday, 24 February 2010 00:00 Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

288

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

289

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

290

Structure Analyses of Artificial Methane Hydrate Sediments by Microfocus X-ray Computed Tomography  

Science Journals Connector (OSTI)

The structure of natural gas hydrate sediments was characterized by microfocus X-ray computed tomography (CT). The obtained two-dimensional (2-D) and three-dimensional (3-D) images clearly showed the spatial distribution of the free-gas spaces, sand particles, and hydrates or ices. The estimated porosity from the X-ray CT data was consistent with the value that was obtained from the sample mass and volume. These results indicate that microfocus X-ray CT can be very useful for researching natural samples of hydrate sediments.

Shigeki Jin; Satoshi Takeya; Junko Hayashi; Jiro Nagao; Yasushi Kamata; Takao Ebinuma; Hideo Narita

2004-01-01T23:59:59.000Z

291

Simultaneous measurement of group refractive index and thickness of optical samples using optical coherence tomography  

SciTech Connect

Optical coherence tomography (OCT), based on a Michelson interferometer and utilizing low coherence light as the optical source, is a novel technique for the noninvasive imaging of optical scattering media. A simple OCT scheme based on a 3x3 fiber coupler is presented for the simultaneous measurement of the refractive index and thickness of optical samples. The proposed system enables the refractive index and thickness to be determined without any prior knowledge of the sample parameters and is characterized by a simple and compact configuration, a straightforward measurement procedure, and a low cost. The feasibility of the proposed approach is demonstrated experimentally using BK7 and B270 optical glass samples.

Cheng, Hsu-Chih; Liu, Yi-Cheng

2010-02-10T23:59:59.000Z

292

Suppression of image autocorrelation artefacts in spectral domain optical coherence tomography and multiwave digital holography  

SciTech Connect

An improved method for suppressing image artefacts in spectral domain optical coherence tomography (SD OCT) and multiwave digital holography, caused by the influence of coherent noise in the course of successive registration of an autocorrelation component and informative signal is reported. The method allows complete suppression of all types of coherent noises, provided that the sample of values used to record the autocorrelation component satisfies the conditions of Kotelnikov's theorem: in SD OCT - for the transverse structure of the studied medium, in multiwave digital holography - for the envelop function of the radiation source frequency tuning spectrum.

Gelikonov, V M; Gelikonov, G V; Terpelov, D A; Shabanov, D V; Shilyagin, P A [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation)

2012-05-31T23:59:59.000Z

293

The use of optical coherence tomography for morphological study of scaffolds  

SciTech Connect

Aimed at possible widening of the optical coherence tomography (OCT) field of application, an attempt is made to use OCT in tissue engineering and cell transplantology as a tool for morphological studies of substrate materials by the example of scaffolds. By means of the traditional fibreoptical OCT scheme the images of inner structure of scaffolds are obtained, and simultaneously the spatial distribution of the intralipid flow velocity is reconstructed using the Doppler OCT. It is shown that combined use of traditional OCT and Doppler OCT schemes allows revealing the regions of the scaffold demonstrating optimal effect of shear stress, which is a key factor of cell growth.

Veksler, B A; Kuz'min, V L; Kobzev, E D; Meglinski, I V

2012-05-31T23:59:59.000Z

294

Positron Emission Tomography-Scanner at Children`s Hospital of Michigan at Detroit, Michigan  

SciTech Connect

The Department of Energy has prepared an environmental assessment (EA), DOE/EA-0795, to support the DOE decision to provide a grant of $7,953,600 to be used in support of a proposed Positron Emission Tomography Scanner at Children`s Hospital of Michigan at Detroit, Michigan. Based upon the analysis in the EA, DOE has determined that the proposed action is not a major Federal action significantly affected the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI).

Not Available

1992-12-31T23:59:59.000Z

295

Chen, Zhao & Jordan Preprint (BSSA) October 6, 2006 1 Full 3D Tomography for Crustal Structure of the Los Angeles Region  

E-Print Network (OSTI)

Chen, Zhao & Jordan Preprint (BSSA) October 6, 2006 1 Full 3D Tomography for Crustal Structure of the Los Angeles Region by Po Chen, Li Zhao and Thomas H. Jordan Abstract We apply full 3D tomography (F3DT. To #12;Chen, Zhao & Jordan Preprint (BSSA) October 6, 2006 2 our knowledge, this study is the first

Chen, Po

296

Using seismic tomography to characterize fracture systems induced by hydraulic fracturing  

SciTech Connect

Microearthquakes induced by hydraulic fracturing have been studied by many investigators to characterize fracture systems created by the fracturing process and to better understand the locations of energy resources in the earth`s subsurface. The pattern of the locations often contains a great deal of information about the fracture system stimulated during the hydraulic fracturing. Seismic tomography has found applications in many areas for characterizing the subsurface of the earth. It is well known that fractures in rock influence both the P and S velocities of the rock. The influence of the fractures is a function of the geometry of the fractures, the apertures and number of fractures, and the presence of fluids in the fractures. In addition, the temporal evolution of the created fracture system can be inferred from the temporal changes in seismic velocity and the pattern of microearthquake locations. Seismic tomography has been used to infer the spatial location of a fracture system in a reservoir that was created by hydraulic fracturing.

Fehler, M.; Rutledge, J.

1995-01-01T23:59:59.000Z

297

Statistical inversion for medical x-ray tomography with few radiographs: II. Application to dental radiology  

Science Journals Connector (OSTI)

Diagnostic and operational tasks in dental radiology often require three-dimensional information that is difficult or impossible to see in a projection image. A CT-scan provides the dentist with comprehensive three-dimensional data. However, often CT-scan is impractical and, instead, only a few projection radiographs with sparsely distributed projection directions are available. Statistical (Bayesian) inversion is well-suited approach for reconstruction from such incomplete data. In statistical inversion, a priori information is used to compensate for the incomplete information of the data. The inverse problem is recast in the form of statistical inference from the posterior probability distribution that is based on statistical models of the projection data and the a priori information of the tissue. In this paper, a statistical model for three-dimensional imaging of dentomaxillofacial structures is proposed. Optimization and MCMC algorithms are implemented for the computation of posterior statistics. Results are given with in vitro projection data that were taken with a commercial intraoral x-ray sensor. Examples include limited-angle tomography and full-angle tomography with sparse projection data. Reconstructions with traditional tomographic reconstruction methods are given as reference for the assessment of the estimates that are based on the statistical model.

V Kolehmainen; S Siltanen; S Järvenpää; J P Kaipio; P Koistinen; M Lassas; J Pirttilä; E Somersalo

2003-01-01T23:59:59.000Z

298

High Quality Image of Biomedical Object by X-ray Refraction Based Contrast Computed Tomography  

SciTech Connect

Recently we have developed a new Computed Tomography (CT) algorithm for refraction contrast that uses the optics of diffraction-enhanced imaging. We applied this new method to visualize soft tissue which is not visualized by the current absorption based contrast. The meaning of the contrast that appears in refraction-contrast X-ray CT images must be clarified from a biologic or anatomic point of view. It has been reported that the contrast is made with the specific gravity map with a range of approximately 10 {mu}arc sec. However, the relationship between the contrast and biologic or anatomic findings has not been investigated, to our knowledge. We compared refraction-contrast X-ray CT images with microscopic X-ray images, and we evaluated refractive indexes of pathologic lesions on phase-contrast X-ray CT images. We focused our attenuation of breast cancer and lung cancer as samples. X-ray refraction based Computed Tomography was appeared to be a pathological ability to depict the boundary between cancer nest and normal tissue, and inner structure of the disease.

Hashimoto, E. [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Maksimenko, A.; Hirano, K.; Hyodo, K. [Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Sugiyama, H. [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Shimao, D. [Department of Health Sciences, Ibaraki prefectural University of Health Sciences, 4669-2Ami, Ami, Inashiki, Ibaraki, 300-0394 (Japan); Nishino, Y.; Ishikawa, T. [RIKEN Harima Institute, 1-1-1 Kouto, Mikazuki, Sayo, Hyogo, 679-5148 (Japan); Yuasa, T. [Department of Bio-system Engineering, Faculty of Engineering Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510 (Japan); Ichihara, S. [Dept. of Path., Nagoya Med. Center, Nat. Hospital Organization, Naka-ku, Nagoya 460-0001 (Japan); Arai, Y. [Matsumoto Dental University, 1980 Hirooka, Shiojiri, Nagano (Japan); Ando, M. [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Inst. of Sci. and Tech., Tokyo Univ. of Science, Yamasaki 2641, Noda, Chiba 278-8510 (Japan)

2007-01-19T23:59:59.000Z

299

Compact cold stage for micro-computerized tomography imaging of chilled or frozen samples  

SciTech Connect

High resolution X-ray microCT (computerized tomography) can be used to image a variety of objects, including temperature-sensitive materials. In cases where the sample must be chilled or frozen to maintain sample integrity, either the microCT machine itself must be placed in a refrigerated chamber, or a relatively expensive commercial cold stage must be purchased. We describe here the design and construction of a low-cost custom cold stage suitable for use in a microCT imaging system. Our device uses a boron nitride sample holder, two-stage Peltier cooler, fan-cooled heat sink, and electronic controller to maintain sample temperatures as low as ?25?°C ± 0.2?°C for the duration of a tomography acquisition. The design does not require modification to the microCT machine, and is easily installed and removed. Our custom cold stage represents a cost-effective solution for refrigerating CT samples for imaging, and is especially useful for shared equipment or machines unsuitable for cold room use.

Hullar, Ted; Anastasio, Cort, E-mail: canastasio@ucdavis.edu [Department of Land, Air, and Water Resources, University of California, Davis, California 95616 (United States)] [Department of Land, Air, and Water Resources, University of California, Davis, California 95616 (United States); Paige, David F. [Paige Instruments, Woodland, California 95776 (United States)] [Paige Instruments, Woodland, California 95776 (United States); Rowland, Douglas J. [Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California, Davis, California 95616 (United States)] [Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California, Davis, California 95616 (United States)

2014-04-15T23:59:59.000Z

300

Three-dimensional seismic tomography with tetrahedra element on isoparametric mapping  

Science Journals Connector (OSTI)

The author has developed a method of three-dimensional seismic tomography on concrete structures. This method is based on ray-trace and identification technique, and the distribution of slowness or energy dissipation is identified based on simultaneously iterative reconstruction technique (SIRT) or the other kind of statistical identification technique. This kind of technique was originally developed for investigation of underground that is called geotomography, however, this technique was difficult to apply to concrete structures because the structures generally have irregular shape. A hexahedral element was implemented by the author to overcome this difficulty based on the idea of isoparametric mapping of hexahedral element on finite element analysis, however, it is still difficult to apply the method to the structures that have highly irregular shape. In this respect, an implementation of tetrahedral element is proposed for the three-dimensional seismic tomography on concrete structures to solve the difficulty in this paper. This implementation is based on the idea of isoparametric mapping as well as the case of hexahedral element and it enables to apply the method to structures of complex shape that is insufficient to represent by hexahedral elements. The validity of the proposed method is checked by some numerical example.

Yoshikazu Kobayashi

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Intracellular trafficking of superparamagnetic iron oxide nanoparticles conjugated with TAT peptide: 3-dimensional electron tomography analysis  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer We study the intracellular localisation of TAT-SPIONs using 3-D electron tomography. Black-Right-Pointing-Pointer 3-D images of TAT-SPIONs in a cell are clearly shown. Black-Right-Pointing-Pointer Release of TAT-SPIONs from endocytic vesicles into the cytoplasm is clearly shown. -- Abstract: Internalisation of nanoparticles conjugated with cell penetrating peptides is a promising approach to various drug delivery applications. Cell penetrating peptides such as transactivating transcriptional activator (TAT) peptides derived from HIV-1 proteins are effective intracellular delivery vectors for a wide range of nanoparticles and pharmaceutical agents thanks to their amicable ability to enter cells and minimum cytotoxicity. Although different mechanisms of intracellular uptake and localisation have been proposed for TAT conjugated nanoparticles, it is necessary to visualise the particles on a 3-D plane in order to investigate the actual intracellular uptake and localisation. Here, we study the intracellular localisation and trafficking of TAT peptide conjugated superparamagnetic ion oxide nanoparticles (TAT-SPIONs) using 3-D electron tomography. 3-D tomograms clearly show the location of TAT-SPIONs in a cell and their slow release from the endocytic vesicles into the cytoplasm. The present methodology may well be utilised for further investigations of the behaviours of nanoparticles in cells and eventually for the development of nano drug delivery systems.

Nair, Baiju G.; Fukuda, Takahiro; Mizuki, Toru; Hanajiri, Tatsuro [Bio-Nano Electronics Research Centre, Toyo University, Saitama 350-8585 (Japan)] [Bio-Nano Electronics Research Centre, Toyo University, Saitama 350-8585 (Japan); Maekawa, Toru, E-mail: maekawa@toyo.jp [Bio-Nano Electronics Research Centre, Toyo University, Saitama 350-8585 (Japan)] [Bio-Nano Electronics Research Centre, Toyo University, Saitama 350-8585 (Japan)

2012-05-18T23:59:59.000Z

302

Simulation of electron-matter interaction during wet-STEM electron tomography  

SciTech Connect

Tomography is an efficient tool to probe the 3 dimensional (3D) structure of materials. In the laboratory, a device has been developed to perform electron tomography in an environmental scanning electron microscopy (ESEM). The configuration of Scanning Transmission Electron Microscopy (STEM) in Environmental Scanning Electron Microscopy (ESEM) provides a novel approach for the characterization of the 3D structure of materials and optimizes a compromise between the resolution level of a few nm and the large tomogram due to the high thickness of transparency. Moreover, STEM allows the observation in 2D of wet samples in an ESEM by finely controlling the sample temperature and the water pressure of the sample environment. It has been recently demonstrated that it was possible to acquire image series of hydrated objects and thus to attain 3D characterization of wet samples. In order to get reliable and quantitative data, the present study deals with the simulation of electron-matter interactions. From such simulation on the MCM-41 material, we determine the minimum quantity of water layer which can be detected on wet materials.

Septiyanto, Rahmat Firman, E-mail: karine.masenelli-varlot@insa-lyon.fr [MATEIS, INSA-Lyon, CNRS UMR5510, F-69621, France and Physics of Electronic Material, Departement of Physics, Faculty of Mathematic and Natural Sciences, ITB Jalan Ganesha No. 10, Bandung 40132 (Indonesia); Masenelli-Varlot, Karine [MATEIS, INSA-Lyon, CNRS UMR5510, F-69621 (France); Iskandar, Ferry [Physics of Electronic Material, Departement of Physics, Faculty of Mathematic and Natural Sciences, ITB Jalan Ganesha No. 10, Bandung 40132 (Indonesia)

2014-02-24T23:59:59.000Z

303

Stimulated dual-band infrared computed tomography: A tool to inspect the aging infrastructure  

SciTech Connect

The authors have developed stimulated dual-band infrared (IR) computed tomography as a tool to inspect the aging infrastructure. The system has the potential to locate and quantify structural damage within airframes and bridge decks. Typically, dual-band IR detection methods improve the signal-to-noise ratio by a factor of ten, compared to single-band IR detection methods. They conducted a demonstration at Boeing using a uniform pulsed-heat source to stimulate IR images of hidden defects in the 727 fuselage. The dual-band IR camera and image processing system produced temperature, thermal inertia, and cooling-rate maps. In combination, these maps characterized the defect site, size, depth, thickness and type. The authors quantified the percent metal loss from corrosion above a threshold of 5%, with overall uncertainties of 3%. Also, they conducted a feasibility study of dual-band IR thermal imaging for bridge deck inspections. They determined the sites and relative concrete displacement of 2-in. and 4-in. deep delaminations from thin styrofoam implants in asphalt-covered concrete slabs. They demonstrated the value of dual-band IR computed tomography to quantify structural damage within flash-heated airframes and naturally-heated bridge decks.

Del Grande, N.K.; Durbin, P.F.

1995-06-27T23:59:59.000Z

304

A new method for imaging nuclear threats using cosmic ray muons  

E-Print Network (OSTI)

Muon tomography is a technique that uses cosmic ray muons to generate three dimensional images of volumes using information contained in the Coulomb scattering of the muons. Advantages of this technique are the ability of cosmic rays to penetrate significant overburden and the absence of any additional dose delivered to subjects under study above the natural cosmic ray flux. Disadvantages include the relatively long exposure times and poor position resolution and complex algorithms needed for reconstruction. Here we demonstrate a new method for obtaining improved position resolution and statistical precision for objects with spherical symmetry.

Morris, C L; Borozdin, Konstantin; Miyadera, Haruo; Perry, John; Rose, Evan; Watson, Scott; White, Timothy; Aberle, Derek; Green, J Andrew; McDuff, George G; Luki?, Zarija; Milner, Edward C

2013-01-01T23:59:59.000Z

305

Neutron tomography of axisymmetric flow fields in porous media A.J. Gilbert, M.R. Deinert  

E-Print Network (OSTI)

Neutron tomography of axisymmetric flow fields in porous media A.J. Gilbert, M.R. Deinert February 2013 Keywords: Preferential flow Wetting front Neutron radiography Image analysis Fingered flow axisymmetric preferential flow fields using neutron radiography. Flow fields such as these are surprisingly

Deinert, Mark

306

Reply to comment on "Electrical Tomography of La Soufrire of Guadeloupe Volcano: Field experiments, 1D inversion and  

E-Print Network (OSTI)

Discussion Reply to comment on "Electrical Tomography of La Soufrière of Guadeloupe Volcano: Field.25.Qi; 91.35.Pn; 91.40.-k; 93.30.Vs 1. Introduction We thank Linde and Revil for their comment [1 and discuss our approach for interpreting electrical resistivity data acquired over complex geological

Beauducel, François

307

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography  

SciTech Connect

In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.

2012-01-10T23:59:59.000Z

308

Link between Tomography and Copula1 Doriano-Boris Pougaza, Ali Mohammad-Djafari, Jean-Francois Bercher2  

E-Print Network (OSTI)

in Computed To- mography (CT) is to reconstruct an image from its projections. In the bivariate case of Environmental Data [2, 3]. Recently, in17 Computational Biology, copulas were used for the reconstructionLink between Tomography and Copula1 Doriano-Boris Pougaza, Ali Mohammad-Djafari, Jean

Bercher, Jean-François

309

Monitoring Carbon Dioxide Sequestration Using Electrical Resistance Tomography (ERT): Sensitivity Studies  

NLE Websites -- All DOE Office Websites (Extended Search)

Monitoring Carbon Dioxide Sequestration Using Electrical Resistance Monitoring Carbon Dioxide Sequestration Using Electrical Resistance Tomography (ERT): Sensitivity Studies Robin L. Newmark (newmark@llnl.gov, 925-423-3644) Abelardo L. Ramirez (ramirez3@llnl.gov; 925-422-6909) William D. Daily (daily1@llnl.gov; 925-422-8623) Lawrence Livermore National Laboratory P.O. Box 808 Livermore, Ca. 94550 Abstract If geologic formations are used to sequester carbon dioxide (CO 2 ), monitoring the CO 2 injection will be required to confirm the performance of the reservoir system, assess leaks and flow paths, and understand the geophysical and geochemical interactions between the CO 2 and the geologic minerals and fluids. Electrical methods are well suited for monitoring processes involving fluids, as electrical properties are sensitive to the

310

Time-dependent seismic tomography of the Coso geothermal area, 1996-2004 |  

Open Energy Info (EERE)

of the Coso geothermal area, 1996-2004 of the Coso geothermal area, 1996-2004 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Time-dependent seismic tomography of the Coso geothermal area, 1996-2004 Details Activities (1) Areas (1) Regions (0) Abstract: Local-earthquake tomographic images were calculated for each of the years 1996 - 2004 using arrival times from the U.S. Navy's permanent seismometer network at the Coso geothermal area, California. The results show irregular strengthening with time of the wave-speed ratio VP/VS at shallow depths. These changes result predominately from progressive relative increase in VS with respect to VP, and could result from processes associated with geothermal operations such as decrease in fluid pressure and the drying of argillaceous minerals such as illite.

311

Storage of Pressuirzed Carbon Dioxide in Coal Observed Using X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

OF PRESSURIZED CARBON DIOXIDE IN COAL OBSERVED USING X-RAY OF PRESSURIZED CARBON DIOXIDE IN COAL OBSERVED USING X-RAY TOMOGRAPHY Jonathan P. Mathews (jpm10@psu.edu; 814 863 6213) Ozgen Karacan, (karacan@pnge.psu.edu; 814 865 9570) Phillip Halleck (phil@pnge.psu.edu; 814 863 1701) Gareth D. Mitchell (n8h@psu.edu; 814 863 6543) Abraham Grader (grader@pnge.psu.edu; 814 863 5813) The Energy Institute & Department of Energy & GeoEnvironmental Engineering 151 Holser Building, The Pennsylvania State University University Park, PA 16802 Introduction The sequestration of CO 2 in coal seams has been proposed as a mitigation strategy for climate change. To maximize sorption potential it is essential that the heterogeneity of the coal seam be represented in the computational models used to predict the complex flow and sorption within

312

NMR tomography of the three-qubit Deutsch-Jozsa algorithm  

SciTech Connect

The optimized version of the Deutsch-Jozsa algorithm proposed by Collins et al. was implemented using the three {sup 19}F nuclear spins of 2,3,4-trifluoroaniline as qubits. To emulate the behavior of pure quantum-mechanical states pseudopure states of the ensemble were prepared prior to execution of the algorithm. Full tomography of the density matrix was employed to obtain detailed information about initial, intermediate, and final states. Information, thus obtained, was applied to optimize the pulse sequences used. It is shown that substantial improvement of the fidelity of the preparation may be achieved by compensating the effects caused by the different relaxation behavior of the different substates of the density matrix. All manipulations of the quantum states were performed under the conditions of unresolved spin-spin interactions.

Mangold, Oliver; Heidebrecht, Andreas; Mehring, Michael [2. Physikalisches Institut, University of Stuttgart, Stuttgart (Germany)

2004-10-01T23:59:59.000Z

313

Using electrokinetic phenomena and electrical resistance tomography to characterize the movement of subsurface fluids  

DOE Patents (OSTI)

This invention relates generally to the remote detections of subsurface liquid contaminants using in combination a geophysical technique known as ERT and an EKS. Electrokinetic transport is used to enhance the ability of electrical resistance tomography (ERT) to detect position and movement of subsurface contaminant liquids, particles or ions. ERT images alone are difficult to interpret because of natural inhomogeneities in soil composition and electrical properties. By subtracting two or more ERT images obtained before and after field induced movement, a high contrast image of a plume of distinct electrokinetic properties can be seen. The invention is applicable to important subsurface characterization problems including, as examples, (1) detection of liquid-saturated plumes of contaminants such as those associated with leaks from underground storage tanks containing hazardous concentrated electrolytes, (2) detection and characterization of soils contaminated with organic pollutants such as droplets of gasoline; and (3) monitoring the progress of electrokinetic containment or clean up of underground contamination.

Ramirez, Abelardo L. (Pleasanton, CA); Cooper, John F. (Oakland, CA); Daily, William D. (Livermore, CA)

1996-01-01T23:59:59.000Z

314

Using electrokinetic phenomena and electrical resistance tomography to characterize the movement of subsurface fluids  

DOE Patents (OSTI)

This invention relates generally to the remote detections of subsurface liquid contaminants using in combination a geophysical technique known as ERT and an EKS. Electrokinetic transport is used to enhance the ability of electrical resistance tomography (ERT) to detect position and movement of subsurface contaminant liquids, particles or ions. ERT images alone are difficult to interpret because of natural inhomogeneities in soil composition and electrical properties. By subtracting two or more ERT images obtained before and after field induced movement, a high contrast image of a plume of distinct electrokinetic properties can be seen. The invention is applicable to important subsurface characterization problems including, as examples, (1) detection of liquid-saturated plumes of contaminants such as those associated with leaks from underground storage tanks containing hazardous concentrated electrolytes, (2) detection and characterization of soils contaminated with organic pollutants such as droplets of gasoline; and (3) monitoring the progress of electrokinetic containment or clean up of underground contamination. 1 fig.

Ramirez, A.L.; Cooper, J.F.; Daily, W.D.

1996-02-27T23:59:59.000Z

315

Atom Probe Tomography Analysis of Precipitation during Tempering of a Nanostructured Bainitic Steel  

SciTech Connect

Carbon distribution during tempering of a nanostructured bainitic steel was analyzed by atom probe tomography (APT). Three different types of particles are detected on samples tempered at 673 K (400 C) for 30 minutes: lower bainite cementite with a carbon content of {approx}25 at. pct, {var_epsilon}-carbides with a carbon content close to 30 at. pct, and carbon clusters, small features with a carbon content of {approx}14 at. pct indicative of a stage of tempering prior to precipitation of {var_epsilon}-carbide. After tempering at 773 K (500 C) for 30 minutes, the {var_epsilon}-carbide-to-cementite transition was observed. Solute concentration profiles across carbide/ferrite interfaces showed the distribution of substitutional elements in {var_epsilon}-carbide and cementite for all the tempering conditions.

Caballero, Francesca G. [CENIM-CSIC, Madrid, Spain; Miller, Michael K [ORNL; Garcia-Mateo, C. [CENIM-CSIC, Madrid, Spain

2011-01-01T23:59:59.000Z

316

Approximate Marginalization of Absorption and Scattering in Fluorescence Diffuse Optical Tomography  

E-Print Network (OSTI)

In fluorescence diffuse optical tomography (fDOT), the reconstruction of the fluorophore concentration inside the target body is usually carried out using a normalized Born approximation model where the measured fluorescent emission data is scaled by measured excitation data. One of the benefits of the model is that it can tolerate inaccuracy in the absorption and scattering distributions that are used in the construction of the forward model to some extent. In this paper, we employ the recently proposed Bayesian approximation error approach to fDOT for compensating for the modeling errors caused by the inaccurately known optical properties of the target in combination with the normalized Born approximation model. The approach is evaluated using a simulated test case with different amount of error in the optical properties. The results show that the Bayesian approximation error approach improves the tolerance of fDOT imaging against modeling errors caused by inaccurately known absorption and scattering of the...

Mozumder, Meghdoot; Arridge, Simon; Kaipio, Jari P; d'Andrea, Cosimo; Kolehmainen, Ville

2015-01-01T23:59:59.000Z

317

Multislice Spiral Computed Tomography of the Heart: Technique, Current Applications, and Perspective  

SciTech Connect

Multislice spiral computed tomography (MSCT) is a rapidly evolving, noninvasive technique for cardiac imaging. Knowledge of the principle of electrocardiogram-gated MSCT and its limitations in clinical routine are needed to optimize image quality. Therefore, the basic technical principle including essentials of image postprocessing is described. Cardiac MSCT imaging was initially focused on coronary calcium scoring, MSCT coronary angiography, and analysis of left ventricular function. Recent studies also evaluated the ability of cardiac MSCT to visualize myocardial infarction and assess valvular morphology. In combination with experimental approaches toward the assessment of aortic valve function and myocardial viability, cardiac MSCT holds the potential for a comprehensive examination of the heart using one single examination technique.

Mahnken, Andreas H., E-mail: mahnken@rad.rad.rwth-aachen.de; Wildberger, Joachim E. [Aachen University of Technology, Department of Diagnostic Radiology (Germany); Koos, Ralf [Aachen University of Technology, Medical Clinic I (Germany); Guenther, Rolf W. [Aachen University of Technology, Department of Diagnostic Radiology (Germany)

2005-05-15T23:59:59.000Z

318

X-ray tomography system to investigate granular materials during mechanical loading  

E-Print Network (OSTI)

We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in-situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3d computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3d-printed particles, we resolve packing features with 0.52 mm resolution in a (60 mm)$^3$ field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

Athanasios G Athanassiadis; Patrick J. La Rivière; Emil Sidky; Charles Pelizzari; Xiaochuan Pan; Heinrich M. Jaeger

2014-06-11T23:59:59.000Z

319

Ultrasonic tomography for in-process measurements of temperature in a multi-phase medium  

DOE Patents (OSTI)

A method and apparatus are described for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.

Beller, L.S.

1993-01-26T23:59:59.000Z

320

Three-dimensional Chemical Imaging of Embedded Nanoparticles using Atom Probe Tomography  

SciTech Connect

Analysis of nanoparticles is often challenging especially when they are embedded in a matrix. Hence, we have used laser-assisted atom probe tomography (APT) to analyze the Au-nanoclusters synthesized in situ using ion beam implantation in single crystal MgO matrix. APT analysis along with scanning transmission electron microscopy and energy dispersive spectroscopy (STEM-EDS) indicated that the nanoparticles have an average size ~ 8 - 12 nm. While it is difficult to analyze the composition of individual nanoparticles using STEM, APT analysis can give three dimensional compositions of the same. It was shown that the maximum Au-concentration in the nanoparticles increases with increasing particle size, with a maximum Au-concentration of up to 50%.

Kuchibhatla, Satyanarayana V N T; Shutthanandan, V.; Prosa, Ty J.; Adusumilli, Praneet; Arey, Bruce W.; Buxbaum, Alex; Wang, Y. C.; Tessner, Ted; Ulfig, Robert M.; Wang, Chong M.; Thevuthasan, Suntharampillai

2012-05-03T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Functional optoacoustic neuro-tomography (FONT) for whole-brain monitoring of calcium indicators  

E-Print Network (OSTI)

Non-invasive observation of spatiotemporal neural activity of large neural populations distributed over entire brains is a longstanding goal of neuroscience. We developed a real-time volumetric and multispectral optoacoustic tomography platform for imaging of neural activation deep in scattering brains. The system can record 100 volumetric frames per second across a 200mm3 field of view and spatial resolutions below 70um. Experiments performed in immobilized and freely swimming larvae and in adult zebrafish brains demonstrate, for the first time, the fundamental ability to optoacoustically track neural calcium dynamics in animals labeled with genetically encoded calcium indicator GCaMP5G, while overcoming the longstanding penetration barrier of optical imaging in scattering brains. The newly developed platform offers unprecedented capabilities for functional whole-brain observations of fast calcium dynamics; in combination with optoacoustics' well-established capacity in resolving vascular hemodynamics, it co...

Sela, Gali; Deán-Ben, X Luís; Kneipp, Moritz; Ntziachristos, Vasilis; Shoham, Shy; Westmeyer, Gil G; Razansky, Daniel

2015-01-01T23:59:59.000Z

322

Estimation of conductivity changes in a region of interest with electrical impedance tomography  

E-Print Network (OSTI)

This paper proposes a novel approach to reconstruct changes in a target conductivity from electrical impedance tomography measurements. As in the conventional difference imaging, the reconstruction of the conductivity change is based on electrical potential measurements from the exterior boundary of the target before and after the change. In this paper, however, images of the conductivity before and after the change are reconstructed simultaneously based on the two data sets. The key feature of the approach is that the conductivity after the change is parameterized as a linear combination of the initial state and the change. This allows for modeling independently the spatial characteristics of the background conductivity and the change of the conductivity - by separate regularization functionals. The approach also allows in a straightforward way the restriction of the conductivity change to a localized region of interest inside the domain. While conventional difference imaging reconstruction is based on a glo...

Liu, Dong; Siltanen, Samuli; Laukkanen, Anne maria; Seppanen, Aku

2014-01-01T23:59:59.000Z

323

Qualification of HTR pebbles by X-ray tomography and thermal analysis  

Science Journals Connector (OSTI)

Knowledge of the TRISO particle distributions inside HTR fuel pebbles or compacts may help manufacturers to improve the quality of their fuel by providing feedback during the development phase. In a joint program, NRG and JRC-IE develop a fast method to obtain these distributions non-destructively, based on X-ray tomography. The coordinates of the individual TRISO particles are extracted from a tomographic reconstruction of a pebble. The particle distributions are then partially characterized by the distributions of nearest neighbor distances. In addition, the temperature distribution during operation is estimated by assigning power to each particle while using the pebble edge temperature as a boundary condition. The whole procedure was applied to 31 pebbles fabricated in the 1980s in the framework of the German HTR fuel qualification program.

P.R. Hania; B. Janssen; A.V. Fedorov; S. Knol; S. de Groot; L. Metten; A. van de Sande; M.A. Fütterer

2012-01-01T23:59:59.000Z

324

Spatial coherence effect on layer thickness determination in narrowband full-field optical coherence tomography  

SciTech Connect

Longitudinal spatial coherence (LSC) is determined by the spatial frequency content of an optical beam. The use of lenses with a high numerical aperture (NA) in full-field optical coherence tomography and a narrowband light source makes the LSC length much shorter than the temporal coherence length, hence suggesting that high-resolution 3D images of biological and multilayered samples can be obtained based on the low LSC. A simplified model is derived, supported by experimental results, which describes the expected interference output signal of multilayered samples when high-NA lenses are used together with a narrowband light source. An expression for the correction factor for the layer thickness determination is found valid for high-NA objectives. Additionally, the method was applied to a strongly scattering layer, demonstrating the potential of this method for high-resolution imaging of scattering media.

Safrani, Avner; Abdulhalim, Ibrahim

2011-06-20T23:59:59.000Z

325

Analysis method of matrix and second phase particles in Zircaloy-2 by atom probe tomography  

Science Journals Connector (OSTI)

Abstract Properties of second-phase particles (SPPs) influence the corrosion resistance and the anti-hydrogen pickup in Zircaloy-2 claddings. The chemical compositions of Zr(Fe,Cr)2 and Zr2(Fe,Ni) \\{SPPs\\} were investigated by means of pulsed laser atom probe tomography. In order to identify the atomic concentration with accuracy, two approaches were applied to the Zr-matrix and the SPPs: the first by using all the visible peaks of the mass spectrum and the second using the representative peaks with the natural abundance of the corresponding isotopes. It was found that the background and tail effects are minimized by the first approach in case of estimating a single phase. The change in the concentration between the Zr-matrix and the \\{SPPs\\} can be estimated more accurately by the second approach, although Sn concentration in the Zr2(Fe,Ni) \\{SPPs\\} is slightly overestimated.

T. Sawabe; T. Sonoda; S. Kitajima

2014-01-01T23:59:59.000Z

326

Magnetic field calculation for a 10 MeV positron emission tomography cyclotron  

SciTech Connect

The magnetic field calculation and correction for a 10 MeV positron emission tomography cyclotron is presented. 3D TOSCA analysis results are compared with the measured data, and the calculation error is used to calibrate the B-H curve to obtain a very precise finite element method estimator, which is used to predict the correction of the magnet pole for achieving the isochronous field. The isochronous field error is approximated with the effects of a set of standard patches. On the assumption that the effect of each small patch is proportional to its surface, the correction of the magnet pole is found by solving a system of equations using the least square scheme. The magnet shimming is performed and the measured magnetic field is found in good agreement with the prediction, with an error less than 2 G.

Chen Dezhi; Liu Kaifeng; Yang Jun; Li Dong; Qin Bin; Xiong Yongqian [State Key Lab of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Chen Zihao [Central Southern Electrical Power Design Institute, Wuhan 430071 (China)

2013-05-15T23:59:59.000Z

327

A Fast local Reconstruction algorithm by selective backprojection for Low-Dose in Dental Computed Tomography  

E-Print Network (OSTI)

High radiation dose in computed tomography (CT) scans increases the lifetime risk of cancer, which become a major clinical concern. The backprojection-filtration (BPF) algorithm could reduce radiation dose by reconstructing images from truncated data in a short scan. In dental CT, it could reduce radiation dose for the teeth by using the projection acquired in a short scan, and could avoid irradiation to other part by using truncated projection. However, the limit of integration for backprojection varies per PI-line, resulting in low calculation efficiency and poor parallel performance. Recently, a tent BPF (T-BPF) has been proposed to improve calculation efficiency by rearranging projection. However, the memory-consuming data rebinning process is included. Accordingly, the chose-BPF (C-BPF) algorithm is proposed in this paper. In this algorithm, the derivative of projection is backprojected to the points whose x coordinate is less than that of the source focal spot to obtain the differentiated backprojection...

Bin, Yan; Yu, Han; Feng, Zhang; Chao, Wang Xian; Lei, Li

2013-01-01T23:59:59.000Z

328

Silicon photomultiplier choice for the scintillating fibre tracker in second generation proton computed tomography scanner  

SciTech Connect

Scintillating fibers are capable of charged particle tracking with high position resolution, as demonstrated by the central fiber tracker of the D0 experiment. The charged particles will deposit less energy in the polystyrene scintillating fibers as opposed to a typical silicon tracker of the same thickness, while SiPM's are highly efficient at detecting photons created by the passage of the charged particle through the fibers. The current prototype of the Proton Computed Tomography (pCT) tracker uses groups of three 0.5 mm green polystyrene based scintillating fibers connected to a single SiPM, while first generation prototype tracker used Silicon strip detectors. The results of R&D for the Scintillating Fiber Tracker (SFT) as part of the pCT detector are outlined, and the premise for the selection of SiPM is discussed.

Gearhart, A.; Johnson, E.; Medvedev, V.; /Northern Illinois U.; Ronzhin, A.; /Fermilab; Rykalin, V.; /Northern Illinois U.; Rubinov, P.; /Fermilab; Sleptcov, V.; /Unlisted, RU

2012-03-01T23:59:59.000Z

329

Digital Radiography and Computed Tomography Project -- Fully Integrated Linear Detector ArrayStatus Report  

SciTech Connect

The field-portable Digital Radiography and Computed Tomography (DRCT) x-ray inspection systems developed for the Project Manager for NonStockpile Chemical Materiel (PMNSCM) over the past 13 years have used linear diode detector arrays from two manufacturers; Thomson and Thales. These two manufacturers no longer produce this type of detector. In the interest of insuring the long term viability of the portable DRCT single munitions inspection systems and to improve the imaging capabilities, this project has been investigating improved, commercially available detectors. During FY-10, detectors were evaluated and one in particular, manufactured by Detection Technologies (DT), Inc, was acquired for possible integration into the DRCT systems. The remainder of this report describes the work performed in FY-11 to complete evaluations and fully integrate the detector onto a representative DRCT platform.

Tim Roney; Robert Seifert; Bob Pink; Mike Smith

2011-09-01T23:59:59.000Z

330

Atomic-scale characterization of germanium isotopic multilayers by atom probe tomography  

SciTech Connect

We report comparison of the interfacial sharpness characterization of germanium (Ge) isotopic multilayers between laser-assisted atom probe tomography (APT) and secondary ion mass spectrometry (SIMS). An alternating stack of 8-nm-thick naturally available Ge layers and 8-nm-thick isotopically enriched {sup 70}Ge layers was prepared on a Ge(100) substrate by molecular beam epitaxy. The APT mass spectra consist of clearly resolved peaks of five stable Ge isotopes ({sup 70}Ge, {sup 72}Ge, {sup 73}Ge, {sup 74}Ge, and {sup 76}Ge). The degree of intermixing at the interfaces between adjacent layers was determined by APT to be around 0.8 {+-} 0.1 nm which was much sharper than that obtained by SIMS.

Shimizu, Y.; Takamizawa, H.; Toyama, T.; Inoue, K.; Nagai, Y. [Oarai Center, Institute for Materials Research, Tohoku University, 2145-2 Narita, Oarai, Ibaraki 311-1313 (Japan); Kawamura, Y.; Uematsu, M.; Itoh, K. M. [School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Haller, E. E. [University of California at Berkeley and Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

2013-01-14T23:59:59.000Z

331

Ultrasonic tomography for in-process measurements of temperature in a multi-phase medium  

DOE Patents (OSTI)

A method and apparatus for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.

Beller, Laurence S. (Idaho Falls, ID)

1993-01-01T23:59:59.000Z

332

Markov Random Field Based Automatic Image Alignment for ElectronTomography  

SciTech Connect

Cryo electron tomography (cryo-ET) is the primary method for obtaining 3D reconstructions of intact bacteria, viruses, and complex molecular machines ([7],[2]). It first flash freezes a specimen in a thin layer of ice, and then rotates the ice sheet in a transmission electron microscope (TEM) recording images of different projections through the sample. The resulting images are aligned and then back projected to form the desired 3-D model. The typical resolution of biological electron microscope is on the order of 1 nm per pixel which means that small imprecision in the microscope's stage or lenses can cause large alignment errors. To enable a high precision alignment, biologists add a small number of spherical gold beads to the sample before it is frozen. These beads generate high contrast dots in the image that can be tracked across projections. Each gold bead can be seen as a marker with a fixed location in 3D, which provides the reference points to bring all the images to a common frame as in the classical structure from motion problem. A high accuracy alignment is critical to obtain a high resolution tomogram (usually on the order of 5-15nm resolution). While some methods try to automate the task of tracking markers and aligning the images ([8],[4]), they require user intervention if the SNR of the image becomes too low. Unfortunately, cryogenic electron tomography (or cryo-ET) often has poor SNR, since the samples are relatively thick (for TEM) and the restricted electron dose usually results in projections with SNR under 0 dB. This paper shows that formulating this problem as a most-likely estimation task yields an approach that is able to automatically align with high precision cryo-ET datasets using inference in graphical models. This approach has been packaged into a publicly available software called RAPTOR-Robust Alignment and Projection estimation for Tomographic Reconstruction.

Moussavi, Farshid; Amat, Fernando; Comolli, Luis R.; Elidan, Gal; Downing, Kenneth H.; Horowitz, Mark

2007-11-30T23:59:59.000Z

333

Addressing the risks of diagnostic radiology : what should be done about the increasing use of computed tomography in the United States  

E-Print Network (OSTI)

Computed tomography (CT) is a prominent procedure in the US with larger radiation doses than traditional radiology. CT is a powerful tool in the diagnosis of a wide variety of conditions and its use has grown quickly because ...

Eastwick, Gary (Gary A.)

2010-01-01T23:59:59.000Z

334

Implementation of sub-nanoseconds TDC in FPGA: applications to time-of-flight analysis in muon radiography  

E-Print Network (OSTI)

Time-of-flight (tof) techniques are standard techniques in high energy physics to determine particles propagation directions. Since particles velocities are generally close to c, the speed of light, and detectors typical dimensions at the meter level, the state-of-the-art tof techniques should reach sub-nanosecond timing resolution. Among the various techniques already available, the recently developed ring oscillator TDC ones, implemented in low cost FPGA, feature a very interesting figure of merit since a very good timing performance may be achieved with limited processing ressources. This issue is relevant for applications where unmanned sensors should have the lowest possible power consumption. Actually this article describes in details the application of this kind of tof technique to muon tomography of geological bodies. Muon tomography aims at measuring density variations and absolute densities through the detection of atmospheric muons flux's attenuation, due to the presence of matter. When the measure...

Marteau, J; Gibert, D; Jourde, K; Gardien, S; Girerd, C; Ianigro, J -C

2014-01-01T23:59:59.000Z

335

Compressive deformation and yielding mechanisms in cellular Al alloys determined using X-ray tomography and surface strain mapping  

SciTech Connect

The mechanisms of compressive deformation that occur in closed cell Al alloys have been established. This has been achieved by using x-ray computed tomography (CT) and surface strain mapping to determine the deformation modes and the cell morphologies that control the onset of yielding. The deformation is found to localize in narrow bands having width of order of a cell diameter. Outside the bands, the material remains elastic. The cells within the bands that experience large permanent strains are primarily elliptical. A group of cells work collectively to allow large localized deformation. Size does not appear to be the initiator of the deformation bands. Equiaxed cells remain elastic. The implications for manufacturing materials with superior mechanical properties are discussed. Visualization of internal deformation of a closed cell Al alloy core, as part of a sandwich panel construction, is also possible using x-ray tomography. Preliminary results for a punch indentation test are presented.

Bart-Smith, H.; Bastawros, A.F.; Mumm, D.R.; Evans, A.G. [Harvard Univ., Cambridge, MA (United States). Div. of Engineering and Applied Sciences; Sypeck, D.J.; Wadley, H.N.G. [Univ. of Virginia, Charlottesville, VA (United States). School of Engineering and Applied Science

1998-12-31T23:59:59.000Z

336

High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography  

SciTech Connect

We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomography (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile, lack of high voltage needed, and their non-sensitivity to magnetic fields. While investigations into this technique have begun elsewhere, we feel that the extensive SiPM characterization and data acquisition expertise of Fermilab, and the historical in-depth research of PET imaging at University of Chicago will combine to make significant strides in this field. We also benefit by a working relationship with the SiPM producer STMicroelectronics (STM).

Ronzhin, A.; Los, S.; Martens, M.; Ramberg, E.; /Fermilab; Kim, H.; Chen, C.; Kao, C.; /Chicago U.; Niessen, K.; /SUNY, Buffalo; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez; Mazzillo, M.; Carbone, B.; /SGS Thomson, Catania

2011-02-01T23:59:59.000Z

337

Volume-Based Parameters of {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Improve Disease Recurrence Prediction in Postmastectomy Breast Cancer Patients With 1 to 3 Positive Axillary Lymph Nodes  

SciTech Connect

Purpose: To determine whether volume-based parameters on pretreatment {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography in breast cancer patients treated with mastectomy without adjuvant radiation therapy are predictive of recurrence. Methods and Materials: We retrospectively analyzed 93 patients with 1 to 3 positive axillary nodes after surgery, who were studied with {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography for initial staging. We evaluated the relationship between positron emission tomography parameters, including the maximum standardized uptake value, metabolic tumor volume (MTV), and total lesion glycolysis (TLG), and clinical outcomes. Results: The median follow-up duration was 45 months. Recurrence was observed in 11 patients. Metabolic tumor volume and TLG were significantly related to tumor size, number of involved nodes, nodal ratio, nuclear grade, estrogen receptor (ER) status, and triple negativity (TN) (all P values were <.05). In receiver operating characteristic curve analysis, MTV and TLG showed better predictive performance than tumor size, ER status, or TN (area under the curve: 0.85, 0.86, 0.79, 0.74, and 0.74, respectively). On multivariate analysis, MTV was an independent prognostic factor of locoregional recurrence-free survival (hazard ratio 34.42, 95% confidence interval 3.94-882.71, P=.0008) and disease-free survival (DFS) (hazard ratio 13.92, 95% confidence interval 2.65-103.78, P=.0018). The 3-year DFS rate was 93.8% for the lower MTV group (<53.1; n=85) and 25.0% for the higher MTV group (?53.1; n=8; P<.0001, log–rank test). The 3-year DFS rate for patients with both ER-positive status and MTV <53.1 was 98.2%; and for those with ER-negative status and MTV ?53.1 it was 25.0% (P<.0001). Conclusions: Volume-based parameters improve recurrence prediction in postmastectomy breast cancer patients with 1 to 3 positive nodes. The addition of MTV to ER status or TN has potential benefits to identify a subgroup at higher risk for recurrence.

Nakajima, Naomi, E-mail: haruhi0321@gmail.com [Department of Radiation Oncology, National Hospital Organization Shikoku Cancer Center, Ehime (Japan); Department of Radiology, Ehime University, Ehime (Japan); Kataoka, Masaaki [Department of Radiation Oncology, National Hospital Organization Shikoku Cancer Center, Ehime (Japan); Sugawara, Yoshifumi [Department of Diagnostic Radiology, National Hospital Organization Shikoku Cancer Center, Ehime (Japan); Ochi, Takashi [Department of Radiology, Ehime University, Ehime (Japan); Kiyoto, Sachiko; Ohsumi, Shozo [Department of Breast Oncology, National Hospital Organization Shikoku Cancer Center, Ehime (Japan); Mochizuki, Teruhito [Department of Radiology, Ehime University, Ehime (Japan)

2013-11-15T23:59:59.000Z

338

3D Tomography of MHD Fluctuations in the H-1NF Heliac  

E-Print Network (OSTI)

A 3D tomographic reconstruction technique which does not rely on a set of radial basis functions is described for inversion of a set of limited-angle high-resolution 2D visible light emission projections (extended in the vertical and toroidal directions) of global MHD eigenmodes in the H-1NF heliac. This paper deals with some of the features and challenges that will arise in the application of tomographic imaging systems to fusion reactors, especially the strong shaping of optimised stellarator/heliotron configurations, and limited access in all types. The fluctuations are represented as a finite sum of Fourier modes characterised by toroidal and poloidal mode numbers having fixed amplitude and phase in a set of nested cylindrical flux volumes in Boozer space. The amplitudes and phases are calculated using iterative tomographic inversion techniques such as ART, SIRT and standard linear least-squares methods. The tomography is applied to synchronous camera images of singly charged carbon impurity ion emission ...

Haskey, S R; Seiwald, B; Howard, J

2014-01-01T23:59:59.000Z

339

Unique Thylakoid Membrane Architecture of a Unicellular N2-Fixing Cyanobacterium Revealed by Electron Tomography  

SciTech Connect

Cyanobacteria, descendants of the endosymbiont that gave rise to modern-day chloroplasts, are vital contributors to global biological energy conversion processes. A thorough understanding of the physiology of cyanobacteria requires detailed knowledge of these organisms at the level of cellular architecture and organization. In these prokaryotes, the large membrane protein complexes of the photosynthetic and respiratory electron transport chains function in the intracellular thylakoid membranes. Like plants, the architecture of the thylakoid membranes in cyanobacteria has direct impact on cellular bioenergetics, protein transport, and molecular trafficking. However, whole-cell thylakoid organization in cyanobacteria is not well understood. Here we present, by using electron tomography, an in-depth analysis of the architecture of the thylakoid membranes in a unicellular cyanobacterium, Cyanothece sp. ATCC 51142. Based on the results of three-dimensional tomographic reconstructions of near-entire cells, we determined that the thylakoids in Cyanothece 51142 form a dense and complex network that extends throughout the entire cell. This thylakoid membrane network is formed from the branching and splitting of membranes and encloses a single lumenal space. The entire thylakoid network spirals as a peripheral ring of membranes around the cell, an organization that has not previously been described in a cyanobacterium. Within the thylakoid membrane network are areas of quasi-helical arrangement with similarities to the thylakoid membrane system in chloroplasts. This cyanobacterial thylakoid arrangement is an efficient means of packing a large volume of membranes in the cell while optimizing intracellular transport and trafficking.

Liberton, Michelle L.; Austin, Jotham R.; Berg, R. H.; Pakrasi, Himadri B.

2011-04-01T23:59:59.000Z

340

An investigation into positron emission tomography contouring methods across two treatment planning systems  

SciTech Connect

Positron emission tomography (PET) imaging has been used to provide additional information regarding patient tumor location, size, and staging for radiotherapy treatment planning purposes. This additional information reduces interobserver variability and produces more consistent contouring. It is well recognized that different contouring methodology for PET data results in different contoured volumes. The goal of this study was to compare the difference in PET contouring methods for 2 different treatment planning systems using a phantom dataset and a series of patient datasets. Contouring methodology was compared on the ADAC Pinnacle Treatment Planning System and the CMS XiO Treatment Planning System. Contours were completed on the phantom and patient datasets using a number of PET contouring methods—the standardized uptake value 2.5 method, 30%, 40%, and 50% of the maximum uptake method and the signal to background ratio method. Differences of >15% were observed for PET-contoured volumes between the different treatment planning systems for the same data and the same PET contouring methodology. Contoured volume differences between treatment planning systems were caused by differences in data formatting and display and the different contouring tools available. Differences in treatment planning system as well as contouring methodology should be considered carefully in dose-volume contouring and reporting, especially between centers that may use different treatment planning systems or those that have several different treatment planning systems.

Young, Tony, E-mail: Tony.Young@sswahs.nsw.gov.au [Liverpool and Macarthur Cancer Therapy Centres, New South Wales (Australia); Som, Seu [Department of Nuclear Medicine and PET, Liverpool Hospital, New South Wales (Australia); South Western Sydney Clinical School, University of New South Wales, New South Wales (Australia); Sathiakumar, Chithradevi [Department of Nuclear Medicine and PET, Liverpool Hospital, New South Wales (Australia); Holloway, Lois [Liverpool and Macarthur Cancer Therapy Centres, New South Wales (Australia); Institute of Medical Physics, University of Sydney, New South Wales (Australia); Center for Medical Radiation Physics, University of Wollongong, New South Wales (Australia)

2013-04-01T23:59:59.000Z

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341

A Novel CBIR Approach to Differential Diagnosis of Liver Tumor on Computed Tomography Images  

Science Journals Connector (OSTI)

Liver tumor is one of the deadliest diseases which can be cured without much difficulty if diagnosed in early stages. Content based image retrieval (CBIR) constitutes an important tool in computer aided diagnosis (CAD) which improves the diagnostic decisions of the radiologist by retrieving similar pathology bearing images from the medical database. In order to assist the radiologist in diagnosis of liver cancer, this paper proposes a novel CBIR based approach for differential diagnosis of liver tumor on computed tomography (CT) images as benign or malign. First, tumor is characterized by extracting its shape features using Fourier descriptors and texture features using MPEG-7 Gabor filter and edge histogram descriptors. Next, the dimensionality of the feature vector is reduced by applying principal component analysis (PCA).Finally, similarity matching process is accelerated using cluster-based indexing. The proposed approach was tested on medical image database consisting of 764 CT images of liver tumor. The experimental results demonstrate that the proposed method can effectively and efficiently retrieve similar case images from the database in response to query image.

Megha.P. Arakeri; G. Ram Mohana Reddy

2012-01-01T23:59:59.000Z

342

Low background high efficiency radiocesium detection system based on positron emission tomography technology  

Science Journals Connector (OSTI)

After the 2011 nuclear power plant accident at Fukushima radiocesium contamination in food became a serious concern in Japan. However low background and high efficiency radiocesium detectors are expensive and huge including semiconductor germanium detectors. To solve this problem we developed a radiocesium detector by employing positron emission tomography (PET) technology. Because 134Cs emits two gamma photons (795 and 605 keV) within 5 ps they can selectively be measured with coincidence. Such major environmental gamma photons as 40K (1.46 MeV) are single photon emitters and a coincidence measurement reduces the detection limit of radiocesium detectors. We arranged eight sets of Bi4 Ge 3O12 (BGO) scintillation detectors in double rings (four for each ring) and measured the coincidence between these detectors using PET data acquisition system. A 50 × 50 × 30 mm BGO was optically coupled to a 2 in. square photomultiplier tube (PMT). By measuring the coincidence we eliminated most single gamma photons from the energy distribution and only detected those from 134Cs at an average efficiency of 12%. The minimum detectable concentration of the system for the 100 s acquisition time is less than half of the food monitor requirements in Japan (25 Bq/kg). These results show that the developed radiocesium detector based on PET technology is promising to detect low level radiocesium.

Seiichi Yamamoto; Yoshimune Ogata

2013-01-01T23:59:59.000Z

343

Data fusion in X-ray computed tomography using a superiorization approach  

SciTech Connect

X-ray computed tomography (CT) is an important and widespread inspection technique in industrial non-destructive testing. However, large-sized and heavily absorbing objects cause artifacts due to either the lack of penetration of the specimen in specific directions or by having data from only a limited angular range of views. In such cases, valuable information about the specimen is not revealed by the CT measurements alone. Further imaging modalities, such as optical scanning and ultrasonic testing, are able to provide data (such as an edge map) that are complementary to the CT acquisition. In this paper, a superiorization approach (a newly developed method for constrained optimization) is used to incorporate the complementary data into the CT reconstruction; this allows precise localization of edges that are not resolvable from the CT data by itself. Superiorization, as presented in this paper, exploits the fact that the simultaneous algebraic reconstruction technique (SART), often used for CT reconstruction, is resilient to perturbations; i.e., it can be modified to produce an output that is as consistent with the CT measurements as the output of unmodified SART, but is more consistent with the complementary data. The application of this superiorized SART method to measured data of a turbine blade demonstrates a clear improvement in the quality of the reconstructed image.

Schrapp, Michael J. [Siemens AG, CT Munich, Germany and Physics Department E21, Technical University of Munich, Munich (Germany)] [Siemens AG, CT Munich, Germany and Physics Department E21, Technical University of Munich, Munich (Germany); Herman, Gabor T. [Department of Computer Science, The Graduate Center, City University of New York, New York, New York 10016 (United States)] [Department of Computer Science, The Graduate Center, City University of New York, New York, New York 10016 (United States)

2014-05-15T23:59:59.000Z

344

Molecular architecture of axonemal microtubule doublets revealedby cryo-electron tomography  

SciTech Connect

The axoneme, which forms the core of eukaryotic flagella and cilia, is one of the largest macromolecular machines with a structure that is largely conserved from protists to mammals. Microtubule doublets are structural components of axonemes containing a number of proteins besides tubulin, and are usually found in arrays of nine doublets arranged around two singlet microtubules. Coordinated sliding of adjacent doublets, which involves a host of other proteins in the axoneme, produces periodic beating movements of the axoneme. We have obtained a 3D density map of intact microtubule doublets using cryo-electron tomography and image averaging. Our map, with a resolution of about 3 nm, provides insights into locations of particular proteins within the doublets and the structural features of the doublets that define their mechanical properties. We identify likely candidates for several of these non-tubulin components of the doublets. This work offers novel insight on how tubulin protofilaments and accessory proteins attach together to form the doublets and provides a structural basis for understanding doublet function in axonemes.

Sui, Haixin; Downing, Kenneth H.

2006-05-22T23:59:59.000Z

345

MAPPING EARTH ANALOGS FROM PHOTOMETRIC VARIABILITY: SPIN-ORBIT TOMOGRAPHY FOR PLANETS IN INCLINED ORBITS  

SciTech Connect

Aiming at obtaining detailed information on the surface environment of Earth analogs, Kawahara and Fujii proposed an inversion technique of annual scattered light curves named spin-orbit tomography (SOT), which enables us to sketch a two-dimensional albedo map from annual variation of the disk-integrated scattered light, and demonstrated the method with a planet in a face-on orbit. We extend it to be applicable to general geometric configurations, including low-obliquity planets like the Earth in inclined orbits. We simulate light curves of the Earth in an inclined orbit in three photometric bands (0.4-0.5 {mu}m, 0.6-0.7 {mu}m, and 0.8-0.9 {mu}m) and show that the distribution of clouds, snow, and continents is retrieved with the aid of the SOT. We also demonstrate the SOT by applying it to an upright Earth, a tidally locked Earth, and Earth analogs with ancient continental configurations. The inversion is model independent in the sense that we do not assume specific albedo models when mapping the surface, and hence applicable in principle to any kind of inhomogeneity. This method can potentially serve as a unique tool to investigate the exohabitats/exoclimes of Earth analogs.

Fujii, Yuka [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Kawahara, Hajime, E-mail: yuka.fujii@utap.phys.s.u-tokyo.ac.jp [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)

2012-08-20T23:59:59.000Z

346

Combined 3D PET and Optical Projection Tomography Techniques for Plant Root Phenotyping  

E-Print Network (OSTI)

New imaging techniques are in great demand for investigating underground plant roots systems which play an important role in crop production. Compared with other non-destructive imaging modalities, PET can image plant roots in natural soil and produce dynamic 3D functional images which reveal the temporal dynamics of plant-environment interactions. In this study, we combined PET with optical projection tomography (OPT) to evaluate its potential for plant root phenotyping. We used a dedicated high resolution plant PET imager that has a 14 cm transaxial and 10 cm axial field of views, and multi-bed imaging capability. The image resolution is around 1.25 mm using ML-EM reconstruction algorithm. B73 inbred maize seeds were germinated and then grown in a sealed jar with transparent gel-based media. PET scanning started on the day when the first green leaf appeared, and was carried out once a day for 5 days. Each morning, around 10 mCi of 11CO2 was administrated into a custom built plant labeling chamber. After 10 ...

Wang, Qiang; Mathews, Aswin J; Li, Ke; Topp, Christopher; O'Sullivan, Joseph A; Tai, Yuan-Chuan

2015-01-01T23:59:59.000Z

347

3D Jet Tomography of Twisted Strongly Coupled Quark Gluon Plasmas  

E-Print Network (OSTI)

The triangular enhancement of the rapidity distribution of hadrons produced in p+A reactions relative to p+p is a leading order in A^{1/3}/log(s) violation of longitudinal boost invariance at high energies. In A+A reactions this leads to a trapezoidal enhancement of the local rapidity density of produced gluons. The local rapidity gradient is proportional to the local participant number asymmetry, and leads to an effective rotation in the reaction plane. We propose that three dimensional jet tomography, correlating the long range rapidity and azimuthal dependences of the nuclear modification factor, R_{AA}(\\eta,\\phi,p_\\perp; b>0), can be used to look for this intrinsic longitudinal boost violating structure of $A+A$ collisions to image the produced twisted strongly coupled quark gluon plasma (sQGP). In addition to dipole and elliptic azimuthal moments of R_{AA}, a significant high p_\\perp octupole moment is predicted away from midrapidity. The azimuthal angles of maximal opacity and hence minima of R_{AA} are rotated away from the normal to the reaction plane by an `Octupole Twist' angle, \\theta_3(\\eta), at forward rapidities.

A. Adil; M. Gyulassy

2005-05-01T23:59:59.000Z

348

Mapping hidden aircraft defects with dual-band infrared computed tomography  

SciTech Connect

Infrared computed tomography (IRCT) is a promising, non-contact, nondestructive evaluation tool used to inspect the mechanical integrity of large structures. We describe on-site, proof-of-principle demonstrations of IRCt to inspect defective metallic and composite structures. The IRCT system captures time sequences of heat-stimulated, dual-band infrared (DBIR) thermal maps for flash-heated and naturally-heated targets. Our VIEW algorithms produce co-registered thermal, thermal inertia, and thermal-timegram maps from which we quantify the percent metal-loss corrosion damage for airframes and the defect sites, depths, and host-material physical properties for composite structures. The IRCT method clarifies the type of defect, e.g., corrosion, fabrication, foreign-material insert, delamination, unbond, void, and quantifies the amount of damage from the defect, e.g., the percent metal-loss from corrosion in metal structures, the depth, thickness, and areal extent of heat damage in multi-layered composite materials. Potential long-term benefits of IRCT technology are in-service monitoring of incipient corrosion damage, to avoid catastrophic failure and production-monitoring of cure states for composite materials.

Del Grande, N.K.; Durbin, P.F.

1995-04-03T23:59:59.000Z

349

Dynamic Inversion for Hydrological Process Monitoring with Electrical Resistance Tomography Under Model Uncertainty  

SciTech Connect

We propose an approach for imaging the dynamics of complex hydrological processes. The evolution of electrically conductive fluids in porous media is imaged using time-lapse electrical resistance tomography. The related dynamic inversion problem is solved using Bayesian filtering techniques, that is, it is formulated as a sequential state estimation problem in which the target is an evolving posterior probability density of the system state. The dynamical inversion framework is based on the state space representation of the system, which involves the construction of a stochastic evolution model and an observation model. The observation model used in this paper consists of the complete electrode model for ERT, with Archie's law relating saturations to electrical conductivity. The evolution model is an approximate model for simulating flow through partially saturated porous media. Unavoidable modeling and approximation errors in both the observation and evolution models are considered by computing approximate statistics for these errors. These models are then included in the construction of the posterior probability density of the estimated system state. This approximation error method allows the use of approximate - and therefore computationally efficient - observation and evolution models in the Bayesian filtering. We consider a synthetic example and show that the incorporation of an explicit model for the model uncertainties in the state space representation can yield better estimates than a frame-by-frame imaging approach.

Lehikoinen, A.; Huttunen, J.M.J.; Finsterle, S.; Kowalsky, M.B.; Kaipio, J.P.

2009-08-01T23:59:59.000Z

350

Combining weak lensing tomography with halo clustering to probe dark energy  

Science Journals Connector (OSTI)

Two methods of constraining the properties of dark energy are weak lensing tomography and cluster counting. Uncertainties in mass calibration of clusters can be reduced by using the properties of halo clustering (the clustering of clusters). However, within a single survey, weak lensing and halo clustering probe the same density fluctuations. We explore the question of whether this information can be used twice—once in weak lensing and then again in halo clustering to calibrate cluster masses—or whether the combined dark energy constraints are weaker than the sum of the individual constraints. For a survey like the Dark Energy Survey (DES), we find that the cosmic shearing of source galaxies at high redshifts is indeed highly correlated with halo clustering at lower redshifts. Surprisingly, this correlation does not degrade cosmological constraints for a DES-like survey, and in fact, constraints are marginally improved since the correlations themselves act as additional observables. This considerably simplifies the analysis for a DES-like survey: when weak lensing and halo clustering are treated as independent experiments, the combined dark energy constraints (cluster counts included) are accurate if not slightly conservative. Our findings mirror those of Takada and Bridle, who investigated correlations between the cosmic shear and cluster counts.

Charles Shapiro and Scott Dodelson

2007-10-18T23:59:59.000Z

351

Experiment Investigation on Concentration and Mass Flow Measurement of Pulverized Coal Using Electrical Capacitance Tomography  

Science Journals Connector (OSTI)

Accurate measurement of the concentration of pulverized coal in various pipes plays a key role in assuring safe and economic operation in a pulverized coal?fired boiler in the process of combustion. In this paper experimental studies are implemented on the measurement of a lean mass flow in a pneumatic conveying pipeline using electrical capacitance tomography (ECT). In this system a cyclone separator is employed where the sensors are placed in order to compensate the inhomogeneity of the sensor sensitivity. The mass flow rate is determined from the solids velocity and the volumetric concentration. The former is measured by cross?correlating the capacitance fluctuations caused by the conveyed solids and the latter by an image reconstruction method and then this two parameters are combined to give the solids mass flow rate. The distribution of void fraction in radial direction the average void fraction and the wavy characteristics are analyzed. The feasibility and reliability of the method are verified by the experimental results.

J. Liu; M. Sun; X. Y. Wang; S. Liu

2010-01-01T23:59:59.000Z

352

Atom Probe Tomography Examination of Carbon Redistribution in Quenched and Tempered 4340 Steel  

SciTech Connect

Quenching and tempering produces a wide range of mechanical properties in medium carbon, low alloyed steels - Study fragmentation behavior as a function of heat-treatment. Subtle microstructural changes accompany the mechanical property changes that result from quenching and tempering - Characterize the location and distribution of carbon and alloying elements in the microstructure using atom probe tomography (APT). Perform complementary transmission electron microscopy (TEM). Tempering influences the mechanical properties and fragmentation of quenched 4340 (hemi-shaped samples). APT revealed carbon-enriched features that contain a maximum of {approx}12-14 at.% carbon after quenching to RT (the level of carbon is perhaps associated with the extent of autotempering). TEM confirmed the presence of twinned martensite and indicates {var_epsilon} ({eta}) transition carbides after oil quenching to RT. Tempering at 325 C resulted in carbon-enriched plates (> 25 at.% C) with no significant element partitioning (transition carbides?). Tempering at 450 C and 575 C resulted in cementite ({approx} 25 at.% C) during late stage tempering; Cr, Mn, Mo partitioned to cementite and Si partitioned to ferrite. Tempering at 575 C resulted in P segregation at cementite interfaces and the formation of Cottrell atmospheres.

Clarke, Amy J. [Los Alamos National Laboratory; Miller, Michael K. [ORNL; Alexander, David J. [Los Alamos National Laboratory; Field, Robert D. [Los Alamos National Laboratory; Clarke, Kester D. [Los Alamos National Laboratory

2012-08-07T23:59:59.000Z

353

Adaptive Radiotherapy for Prostate Cancer Using Kilovoltage Cone-Beam Computed Tomography: First Clinical Results  

SciTech Connect

Purpose: To evaluate the first clinical results of an off-line adaptive radiotherapy (ART) protocol for prostate cancer using kilovoltage cone-beam computed tomography (CBCT) in combination with a diet and mild laxatives. Methods and Materials: Twenty-three patients began treatment with a planning target volume (PTV) margin of 10 mm. The CBCT scans acquired during the first six fractions were used to generate an average prostate clinical target volume (AV-CTV), and average rectum (AV-Rect). Using these structures, a new treatment plan was generated with a 7-mm PTV margin. Weekly CBCT scans were used to monitor the CTV coverage. A diet and mild laxatives were introduced to improve image quality and reduce prostate motion. Results: Twenty patients were treated with conform ART protocol. For these patients, 91% of the CBCT scans could be used to calculate the AV-CTV and AV-Rect. In 96% of the follow-up CBCT scans, the CTV was located within the average PTV. In the remaining 4%, the prostate extended the PTV by a maximum of 1 mm. Systematic and random errors for organ motion were reduced by a factor of two compared with historical data without diet and laxatives. An average PTV reduction of 29% was achieved. The volume of the AV-Rect that received >65 Gy was reduced by 19%. The mean dose to the anal wall was reduced on average by 4.8 Gy. Conclusions: We safely reduced the high-dose region by 29%. The reduction in irradiated volume led to a significant reduction in the dose to the rectum. The diet and laxatives improved the image quality and tended to reduce prostate motion.

Nijkamp, Jasper [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Pos, Floris J. [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)], E-mail: f.pos@nki.nl; Nuver, Tonnis T.; Jong, Rianne de; Remeijer, Peter; Sonke, Jan-Jakob; Lebesque, Joos V. [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

2008-01-01T23:59:59.000Z

354

Cone-beam Computed Tomography-guided Stereotactic Liver Punctures: A Phantom Study  

SciTech Connect

Purpose: Images from computed tomography (CT), combined with navigation systems, improve the outcomes of local thermal therapies that are dependent on accurate probe placement. Although the usage of CT is desired, its availability for time-consuming radiological interventions is limited. Alternatively, three-dimensional images from C-arm cone-beam CT (CBCT) can be used. The goal of this study was to evaluate the accuracy of navigated CBCT-guided needle punctures, controlled with CT scans. Methods: Five series of five navigated punctures were performed on a nonrigid phantom using a liver specific navigation system and CBCT volumetric dataset for planning and navigation. To mimic targets, five titanium screws were fixed to the phantom. Target positioning accuracy (TPE{sub CBCT}) was computed from control CT scans and divided into lateral and longitudinal components. Additionally, CBCT-CT guidance accuracy was deducted by performing CBCT-to-CT image coregistration and measuring TPE{sub CBCT-CT} from fused datasets. Image coregistration was evaluated using fiducial registration error (FRE{sub CBCT-CT}) and target registration error (TRE{sub CBCT-CT}). Results: Positioning accuracies in lateral directions pertaining to CBCT (TPE{sub CBCT} = 2.1 {+-} 1.0 mm) were found to be better to those achieved from previous study using CT (TPE{sub CT} = 2.3 {+-} 1.3 mm). Image coregistration error was 0.3 {+-} 0.1 mm, resulting in an average TRE of 2.1 {+-} 0.7 mm (N = 5 targets) and average Euclidean TPE{sub CBCT-CT} of 3.1 {+-} 1.3 mm. Conclusions: Stereotactic needle punctures might be planned and performed on volumetric CBCT images and controlled with multidetector CT with positioning accuracy higher or similar to those performed using CT scanners.

Toporek, Grzegorz, E-mail: grzegorz.toporek@artorg.unibe.ch; Wallach, Daphne, E-mail: daphne.wallach@artorg.unibe.ch; Weber, Stefan [ARTORG Center for Biomedical Engineering Research, University of Bern (Switzerland)] [ARTORG Center for Biomedical Engineering Research, University of Bern (Switzerland); Bale, Reto; Widmann, Gerlig [Innsbruck Medical University, Section of Microinvasive Therapy, Department of Radiology (Austria)] [Innsbruck Medical University, Section of Microinvasive Therapy, Department of Radiology (Austria)

2013-12-15T23:59:59.000Z

355

Characterization of conditional state-engineering quantum processes by coherent state quantum process tomography  

E-Print Network (OSTI)

Conditional quantum optical processes enable a wide range of technologies from generation of highly non-classical states to implementation of quantum logic operations. The process fidelity that can be achieved in a realistic implementation depends on a number of system parameters. Here we experimentally examine Fock-state filtration, a canonical example of a broad class of conditional quantum operations acting on a single optical field mode. This operation is based upon interference of the mode to be manipulated with an auxiliary single-photon state at a beam splitter, resulting in the entanglement of the two output modes. A conditional projective measurement onto a single photon at one output mode heralds the success of the process. This operation, which implements a measurement-induced nonlinearity, is capable of suppressing particular photon-number probability amplitudes of an arbitrary quantum state. We employ coherent-state process tomography to determine the precise operation realized in our experiment. To identify the key sources of experimental imperfection, we develop a model of the process and identify three main contributions that significantly hamper its efficacy. The reconstructed tensor is compared with a model of the process taking into account sources of experimental imperfection with fidelity better than 0.95. This enables us to identify three key challenges to overcome in realizing a filter with high fidelity - namely the single-photon nature of the auxiliary state, high-mode overlap, and the need for number resolving detection when heralding. The results show that the filter does indeed exhibit a nonlinear response as a function of input photon number and preserves the phase relation between Fock layers of the output state, providing promise for future applications.

Merlin Cooper; Eirion Slade; Michal Karpinski; Brian J. Smith

2014-10-25T23:59:59.000Z

356

A CLIPPING METHOD TO MITIGATE THE IMPACT OF CATASTROPHIC PHOTOMETRIC REDSHIFT ERRORS ON WEAK LENSING TOMOGRAPHY  

SciTech Connect

We use a mock catalog of galaxies based on the COSMOS galaxy catalog, including information on photometric redshift (photo-z) and spectral energy distribution types of galaxies, in order to study how to define a galaxy subsample suitable for weak lensing tomography feasible with optical (and near-IR) multi-band data. Since most useful cosmological information arises from the sample variance limited regime for upcoming lensing surveys, a suitable subsample can be obtained by discarding a large fraction of galaxies that have less reliable photo-z estimations. We develop a method to efficiently identify photo-z outliers by monitoring the width of the posterior likelihood function of redshift estimation for each galaxy. This clipping method may allow us to obtain clean tomographic redshift bins (here three bins are considered) that have almost no overlap, by discarding more than {approx}70% of galaxies with ill-defined photo-zs corresponding to the number densities of remaining galaxies less than {approx}20 arcmin{sup -2} for a Subaru-type deep survey. Restricting the ranges of magnitudes and redshifts and/or adding near-IR data help us obtain a cleaner redshift binning. Using the Fisher information matrix formalism, we propagate photo-z errors into biases in the dark energy equation of state parameter w. We find that, by discarding most of the ill-defined photo-z galaxies, the bias in w can be reduced to a level comparable to the marginalized statistical error; however, the residual small systematic bias remains due to asymmetric scatters around the relation between photometric and true redshifts. We also use the mock catalog to estimate the cumulative signal-to-noise ratios (S/Ns) for measuring the angular cross-correlations of galaxies between finer photo-z bins, finding higher S/N values for the bins that include photo-z outliers.

Nishizawa, Atsushi J. [Astronomical Institute, Tohoku University, Aramaki Aobaku, Sendai 980-8578 (Japan); Takada, Masahiro [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwa-no-Ha, Kashiwa City, Chiba 277-8582 (Japan); Hamana, Takashi; Furusawa, Hisanori, E-mail: nishizawa@astr.tohoku.ac.j [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka City, Tokyo 181-8588 (Japan)

2010-08-01T23:59:59.000Z

357

Dose calculation errors due to inaccurate representation of heterogeneity correction obtained from computerized tomography  

SciTech Connect

Computerized tomography (CT) is used routinely in evaluating radiation therapy isodose plans. With the introduction of 3D algorithms such as the voxel raytrace, which determines inhomogeneity corrections from actual CT Hounsfield numbers, caution must be used when evaluating isodose calculations. Artifacts from contrast media and dental work, radiopaque markers placed by the treatment planner, and changing bowel and rectal air patterns all have the potential to introduce error into the calculation due to inaccurate assessment of high or low density. Radiopaque makers such as x-spot BB's or solder wire are placed externally on the patient. Barium contrast media introduced at the time of simulation may be necessary to visualize specific anatomical structures on the CT images. While these localization and visualization tools may be necessary, it is important to understand the effects they may introduce in the planning process. Other problems encountered are patient specific and out of the control of the treatment planner. These include high- and low-density streaking caused by dental work, which produce computational errors due to overestimation, and small bowel and rectal air, the patterns of which change on a daily basis and may result in underestimation of structure density. It is important for each treatment planner to have an understanding of how this potentially tainted CT information may be applied in dose calculations and the possible effects they may have. At our institution, the voxel raytrace calculation is automatically forced any time couch angle is introduced. Errors in the calculation from the above mentioned situations may be introduced if a heterogeneity correction is applied. Examples of potential calculation errors and the magnitude of each will be discussed. The methods used to minimize these errors and the possible solutions will also be evaluated.

Williams, Greg; Tobler, Matthew; Gaffney, David; Moeller, John; Leavitt, Dennis

2002-12-31T23:59:59.000Z

358

Atom probe tomography characterisation of a laser diode structure grown by molecular beam epitaxy  

SciTech Connect

Atom probe tomography (APT) has been used to achieve three-dimensional characterization of a III-nitride laser diode (LD) structure grown by molecular beam epitaxy (MBE). Four APT data sets have been obtained, with fields of view up to 400 nm in depth and 120 nm in diameter. These data sets contain material from the InGaN quantum well (QW) active region, as well as the surrounding p- and n-doped waveguide and cladding layers, enabling comprehensive study of the structure and composition of the LD structure. Two regions of the same sample, with different average indium contents (18% and 16%) in the QW region, were studied. The APT data are shown to provide easy access to the p-type dopant levels, and the composition of a thin AlGaN barrier layer. Next, the distribution of indium within the InGaN QW was analyzed, to assess any possible inhomogeneity of the distribution of indium (''indium clustering''). No evidence for a statistically significant deviation from a random distribution was found, indicating that these MBE-grown InGaN QWs do not require indium clusters for carrier localization. However, the APT data show steps in the QW interfaces, leading to well-width fluctuations, which may act to localize carriers. Additionally, the unexpected presence of a small amount (x = 0.005) of indium in a layer grown intentionally as GaN was revealed. Finally, the same statistical method applied to the QW was used to show that the indium distribution within a thick InGaN waveguide layer in the n-doped region did not show any deviation from randomness.

Bennett, Samantha E.; Humphreys, Colin J.; Oliver, Rachel A. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Smeeton, Tim M.; Hooper, Stewart E.; Heffernan, Jonathan [Sharp Laboratories of Europe Limited, Edmund Halley Road, Oxford Science Park, Oxford, OX4 4GB (United Kingdom); Saxey, David W.; Smith, George D. W. [Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH (United Kingdom)

2012-03-01T23:59:59.000Z

359

Design of Mega-Voltage X-ray Digital Radiography and Computed Tomography Performance Phantoms  

SciTech Connect

A number of fundamental scientific questions have arisen concerning the operation of high-energy DR and CT systems. Some of these questions include: (1) How deeply can such systems penetrate thickly shielded objects? (2) How well can such systems distinguish between dense and relatively high Z materials such as lead, tungsten and depleted uranium and lower Z materials such as steel, copper and tin? (3) How well will such systems operate for a uranium material which is an intermediate case between low density yellowcake and high density depleted uranium metal? These questions have led us to develop a set of phantoms to help answer these questions, but do not have any direct bearing on any smuggling concern. These new phantoms are designed to allow a systemic exploration of these questions by gradually varying their compositions and thicknesses. These phantoms are also good probes of the blurring behavior of radiography and tomography systems. These phantoms are composed of steel ({rho} assumed to be 7.8 g/cc), lead ({rho} assumed to be 11.4 g/cc), tungsten ({rho} assumed to be 19.25 g/cc), uranium oxide (UO{sub 3}) ({rho} assumed to be 4.6 g/cc), and depleted uranium (DU) ({rho} assumed to be 18.9 g/cc). There are five designed phantoms described in this report: (1) Cylindrical shells of Tungsten and Steel; (2) Depleted Uranium Inside Tungsten Hemi-cube Shells; (3) Nested Spherical Shells; (4) UO{sub 3} Cylinder; and (5) Shielded DU Sphere.

Aufderheide, M B; Martz, H E; Curtin, M

2009-06-22T23:59:59.000Z

360

Respiratory triggered 4D cone-beam computed tomography: A novel method to reduce imaging dose  

SciTech Connect

Purpose: A novel method called respiratory triggered 4D cone-beam computed tomography (RT 4D CBCT) is described whereby imaging dose can be reduced without degrading image quality. RT 4D CBCT utilizes a respiratory signal to trigger projections such that only a single projection is assigned to a given respiratory bin for each breathing cycle. In contrast, commercial 4D CBCT does not actively use the respiratory signal to minimize image dose. Methods: To compare RT 4D CBCT with conventional 4D CBCT, 3600 CBCT projections of a thorax phantom were gathered and reconstructed to generate a ground truth CBCT dataset. Simulation pairs of conventional 4D CBCT acquisitions and RT 4D CBCT acquisitions were developed assuming a sinusoidal respiratory signal which governs the selection of projections from the pool of 3600 original projections. The RT 4D CBCT acquisition triggers a single projection when the respiratory signal enters a desired acquisition bin; the conventional acquisition does not use a respiratory trigger and projections are acquired at a constant frequency. Acquisition parameters studied were breathing period, acquisition time, and imager frequency. The performance of RT 4D CBCT using phase based and displacement based sorting was also studied. Image quality was quantified by calculating difference images of the test dataset from the ground truth dataset. Imaging dose was calculated by counting projections. Results: Using phase based sorting RT 4D CBCT results in 47% less imaging dose on average compared to conventional 4D CBCT. Image quality differences were less than 4% at worst. Using displacement based sorting RT 4D CBCT results in 57% less imaging dose on average, than conventional 4D CBCT methods; however, image quality was 26% worse with RT 4D CBCT. Conclusions: Simulation studies have shown that RT 4D CBCT reduces imaging dose while maintaining comparable image quality for phase based 4D CBCT; image quality is degraded for displacement based RT 4D CBCT in its current implementation.

Cooper, Benjamin J. [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006, Australia and Department of Medical Physics and Radiation Engineering, Canberra Hospital, Canberra, ACT 2605 (Australia); O'Brien, Ricky T.; Keall, Paul J. [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006 (Australia); Balik, Salim; Hugo, Geoffrey D. [Radiation Oncology, Virginia Commonwealth University, 401 College Street, P.O.Box 980058, Richmond, Virginia 23298-0058 (United States)

2013-04-15T23:59:59.000Z

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361

Experimental Investigation of Material Flows Within FSWs Using 3D Tomography  

SciTech Connect

There exists significant prior work using tracers or pre-placed hardened markers within friction stir welding (FSWing) to experimentally explore material flow within the FSW process. Our experiments replaced markers with a thin sheet of copper foil placed between the 6061 aluminum lap and butt joints that were then welded. The absorption characteristics of x-rays for copper and aluminum are significantly different allowing for non-destructive evaluation (NDE) methods such as x-ray computed tomography (CT) to be used to demonstrate the material movement within the weldment on a much larger scale than previously shown. 3D CT reconstruction of the copper components of the weldment allows for a unique view into the final turbulent state of the welding process as process parameters are varied. The x-ray CT data of a section of the weld region was collected using a cone-beam x-ray imaging system developed at the INL. Six-hundred projections were collected over 360-degrees using a 160-kVp Bremsstrahlung x-ray generator (25-micrometer focal spot) and amorphoussilicon x-ray detector. The region of the object that was imaged was about 3cm tall and 1.5cm x 1cm in cross section, and was imaged at a magnification of about 3.6x. The data were reconstructed on a 0.5x0.5x0.5 mm3 voxel grid. After reconstruction, the aluminum and copper could be easily discriminated using a gray level threshold allowing visualization of the copper components. Fractal analysis of the tomographic reconstructed material topology is investigated as a means to quantify macro level material flow based on process parameters. The results of multi-pass FSWs show increased refinement of the copper trace material. Implications of these techniques for quantifying process flow are discussed.

Charles R. Tolle; Timothy A. White; Karen S. Miller; Denis E. Clark; Herschel B. Smartt

2008-06-01T23:59:59.000Z

362

PILOT-SCALE FIELD VALIDATION OF THE LONG ELECTRODE ELECTRICAL RESISTIVITY TOMOGRAPHY METHOD  

SciTech Connect

Field validation for the long electrode electrical resistivity tomography (LE-ERT) method was attempted in order to demonstrate the performance of the technique in imaging a simple buried target. The experiment was an approximately 1/17 scale mock-up of a region encompassing a buried nuclear waste tank on the Hanford site. The target of focus was constructed by manually forming a simulated plume within the vadose zone using a tank waste simulant. The LE-ERT results were compared to ERT using conventional point electrodes on the surface and buried within the survey domain. Using a pole-pole array, both point and long electrode imaging techniques identified the lateral extents of the pre-formed plume with reasonable fidelity, but the LE-ERT was handicapped in reconstructing the vertical boundaries. The pole-dipole and dipole-dipole arrays were also tested with the LE-ERT method and were shown to have the least favorable target properties, including the position of the reconstructed plume relative to the known plume and the intensity of false positive targets. The poor performance of the pole-dipole and dipole-dipole arrays was attributed to an inexhaustive and non-optimal coverage of data at key electrodes, as well as an increased noise for electrode combinations with high geometric factors. However, when comparing the model resolution matrix among the different acquisition strategies, the pole-dipole and dipole-dipole arrays using long electrodes were shown to have significantly higher average and maximum values than any pole-pole array. The model resolution describes how well the inversion model resolves the subsurface. Given the model resolution performance of the pole-dipole and dipole-dipole arrays, it may be worth investing in tools to understand the optimum subset of randomly distributed electrode pairs to produce maximum performance from the inversion model.

GLASER DR; RUCKER DF; CROOK N; LOKE MH

2011-07-14T23:59:59.000Z

363

Comparison of electrical capacitance tomography and gamma densitometer measurement in viscous oil-gas flows  

SciTech Connect

Multiphase flow is a common occurrence in industries such as nuclear, process, oil and gas, food and chemical. A prior knowledge of its features and characteristics is essential in the design, control and management of such processes due to its complex nature. Electrical Capacitance Tomography (ECT) and Gamma Densitometer (Gamma) are two promising approaches for multiphase visualization and characterization in process industries. In two phase oil and gas flow, ECT and Gamma are used in multiphase flow monitoring techniques due to their inherent simplicity, robustness, and an ability to withstand wide range of operational temperatures and pressures. High viscous oil (viscosity > 100 cP) is of interest because of its huge reserves, technological advances in its production and unlike conventional oil (oil viscosity < 100 cP) and gas flows where ECT and Gamma have been previously used, high viscous oil and gas flows comes with certain associated concerns which include; increased entrainment of gas bubbles dispersed in oil, shorter and more frequent slugs as well as oil film coatings on the walls of flowing conduits. This study aims to determine the suitability of both devices in the visualization and characterization of high-viscous oil and gas flow. Static tests are performed with both devices and liquid holdup measurements are obtained. Dynamic experiments were also conducted in a 1 and 3 inch facility at Cranfield University with a range of nominal viscosities (1000, 3000 and 7500 cP). Plug, slug and wavy annular flow patterns were identified by means of Probability Mass Function and time series analysis of the data acquired from Gamma and ECT devices with high speed camera used to validate the results. Measured Liquid holdups for both devices were also compared.

Archibong Eso, A.; Zhao, Yabin; Yeung, Hoi [Department of Offshore Process and Energy Systems Engineering, Cranfield University, Cranfield (United Kingdom)

2014-04-11T23:59:59.000Z

364

A New Tomography Beamline at a Wiggler Port at the Center for Advanced Microstructures and Devices (CAMD) Storage Ring  

Science Journals Connector (OSTI)

A new tomography beamline has been built and commissioned at the 7 T wiggler of the CAMD storage ring. This beamline is equipped with two monochromators that can be used interchangeably for X?ray absorption spectroscopy or high resolution X?ray tomography at best 2–3 ?m pixel size. The high?flux double multilayer?mirror monochromator (W?B4C multilayers) can be used in the energy range from 6 to 35 keV with a resolution (?E/E ) between 0.01–0.03. The second is a channel?cut Si(311)?crystal monochromator with a range of 15 to 36 keV and resolution of ca. 10?4 this is not yet tested. Tomography has the potential for high?throughput materials analysis; however there are some significant obstacles to be overcome in the areas of data acquisition reconstruction visualization and analysis. Data acquisition is facilitated by the multilayer monochromator as this provides high photon flux thus reducing measurement time. At the beamline Matlab© routines provide simple x y z fly?throughs of the sample. Off?beamline processing with Amira© can yield more sophisticated inspection of the sample. Standard data acquisition based on fixed angle increments is not optimal however new patterns based on Greek golden ratio angle increments offer faster convergence to a high signal?to?noise?ratio image. The image reconstruction has traditionally been done by back?projection reconstruction. In this presentation we will show first results from samples studied at the new beamline.

Kyungmin Ham; Heath A. Barnett; Leslie G. Butler; Clinton S. Willson; Kevin J. Morris; Roland C. Tittsworth; John D. Scott

2007-01-01T23:59:59.000Z

365

Structural Investigation of Methane Hydrate Sediments by Microfocus X-ray Computed Tomography Technique under High-Pressure Conditions  

Science Journals Connector (OSTI)

The structure of natural gas hydrate sediments was observed by microfocus X-ray computed tomography (CT). A newly developed high-pressure vessel for the microfocus X-ray CT system was applied to observe the sediments at a temperature above 273 K and under high-pressure conditions. The obtained two-dimensional CT images clearly showed the spatial distribution of the free-gas pore, sand particles, water, and hydrates. These results demonstrated that microfocus X-ray CT can be effective for studying natural gas hydrate sediment samples.

Shigeki Jin; Jiro Nagao; Satoshi Takeya; Yusuke Jin; Junko Hayashi; Yasushi Kamata; Takao Ebinuma; Hideo Narita

2006-01-01T23:59:59.000Z

366

Role of Photoexcitation and Field Ionization in the Measurement of Accurate Oxide Stoichiometry by Laser-Assisted Atom Probe Tomography  

SciTech Connect

Pulsed lasers extend the high spatial and mass resolution of atom probe tomography (APT) to non-conducting materials, such as oxides. For prototypical metal oxide MgO, measured stoichiometry depends strongly upon pulse energy and applied voltage. Very low laser energies (0.02 pJ) and high electric fields yield optimal stoichiometric accuracy, attributed to the field-dependent ionization of photo-desorbed O or O2 neutrals. This emphasizes the importance of considering electronic excitations in APT analysis of oxides ionic materials.

Devaraj, Arun; Colby, Robert J.; Hess, Wayne P.; Perea, Daniel E.; Thevuthasan, Suntharampillai

2013-03-06T23:59:59.000Z

367

Construction and Test of Low Cost X-Ray Tomography Scanner for Physical-Chemical Analysis and Nondestructive Inspections  

SciTech Connect

X-ray computed tomography (CT) refers to the cross-sectional imaging of an object measuring the transmitted radiation at different directions. In this work, we describe the development of a low cost micro-CT X-ray scanner that is being developed for nondestructive testing. This tomograph operates using a microfocus X-ray source and contains a silicon photodiode as detectors. The performance of the system, by its spatial resolution, has been estimated through its Modulation Transfer Function-MTF and the obtained value at 10% of MTF is 661 {mu}m. It was built as a general purpose nondestructive testing device.

Oliveira, Jose Martins Jr. de [Universidade de Sorocaba-UNISO, Campus Seminario, Caixa Postal 578, Av. Dr. Eugenio Salermo, 100, Centro, 18035-430, Sorocaba, SP (Brazil); Martins, Antonio Cesar Germano [Universidade Estadual Paulista Julio de Mesquita Filho-UNESP, GASI, Av. 3 de Marco, 511, Alto da Boa Vista, 18087-180, Sorocaba, SP (Brazil)

2009-06-03T23:59:59.000Z

368

Dopant characterization in self-regulatory plasma doped fin field-effect transistors by atom probe tomography  

SciTech Connect

Fin field-effect transistors are promising next-generation electronic devices, and the identification of dopant positions is important for their accurate characterization. We report atom probe tomography (APT) of silicon fin structures prepared by a recently developed self-regulatory plasma doping (SRPD) technique. Trenches between fin-arrays were filled using a low-energy focused ion beam to directly deposit silicon, which allowed the analysis of dopant distribution by APT near the surface of an actual fin transistor exposed to air. We directly demonstrate that SRPD can achieve a boron concentration above 1 x 10{sup 20} atoms/cm{sup 3} at the fin sidewall.

Takamizawa, H.; Shimizu, Y.; Nozawa, Y.; Toyama, T.; Nagai, Y. [Oarai Center, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Morita, H.; Yabuuchi, Y.; Ogura, M. [Panasonic Corporation, Moriguchi, Osaka 570-8501 (Japan)

2012-02-27T23:59:59.000Z

369

Enhancement of the resolution of full-field optical coherence tomography by using a colour image sensor  

SciTech Connect

The influence of white balance in a colour image detector on the resolution of a full-field optical coherence tomograph (FFOCT) is studied. The change in the interference pulse width depending on the white balance tuning is estimated in the cases of a thermal radiation source (incandescent lamp) and a white light emitting diode. It is shown that by tuning white balance of the detector in a certain range, the FFOCT resolution can be increased by 20 % as compared to the resolution, attained with the use of a monochrome detector. (optical coherence tomography)

Kalyanov, A L; Lychagov, V V; Smirnov, I V; Ryabukho, V P [N.G. Chernyshevsky Saratov State University, Saratov (Russian Federation)

2013-08-31T23:59:59.000Z

370

Nonrigid registration-based coronary artery motion correction for cardiac computed tomography  

SciTech Connect

Purpose: X-ray computed tomography angiography (CTA) is the modality of choice to noninvasively monitor and diagnose heart disease with coronary artery health and stenosis detection being of particular interest. Reliable, clinically relevant coronary artery imaging mandates high spatiotemporal resolution. However, advances in intrinsic scanner spatial resolution (CT scanners are available which combine nearly 900 detector columns with focal spot oversampling) can be tempered by motion blurring, particularly in patients with unstable heartbeats. As a result, recently numerous methods have been devised to improve coronary CTA imaging. Solutions involving hardware, multisector algorithms, or {beta}-blockers are limited by cost, oversimplifying assumptions about cardiac motion, and populations showing contraindications to drugs, respectively. This work introduces an inexpensive algorithmic solution that retrospectively improves the temporal resolution of coronary CTA without significantly affecting spatial resolution. Methods: Given the goal of ruling out coronary stenosis, the method focuses on 'deblurring' the coronary arteries. The approach makes no assumptions about cardiac motion, can be used on exams acquired at high heart rates (even over 75 beats/min), and draws on a fast and accurate three-dimensional (3D) nonrigid bidirectional labeled point matching approach to estimate the trajectories of the coronary arteries during image acquisition. Motion compensation is achieved by employing a 3D warping of a series of partial reconstructions based on the estimated motion fields. Each of these partial reconstructions is created from data acquired over a short time interval. For brevity, the algorithm 'Subphasic Warp and Add' (SWA) reconstruction. Results: The performance of the new motion estimation-compensation approach was evaluated by a systematic observer study conducted using nine human cardiac CTA exams acquired over a range of average heart rates between 68 and 86 beats/min. Algorithm performance was based-lined against exams reconstructed using standard filtered-backprojection (FBP). The study was performed by three experienced reviewers using the American Heart Association's 15-segment model. All vessel segments were evaluated to quantify their viability to allow a clinical diagnosis before and after motion estimation-compensation using SWA. To the best of the authors' knowledge this is the first such observer study to show that an image processing-based software approach can improve the clinical diagnostic value of CTA for coronary artery evaluation. Conclusions: Results from the observer study show that the SWA method described here can dramatically reduce coronary artery motion and preserve real pathology, without affecting spatial resolution. In particular, the method successfully mitigated motion artifacts in 75% of all initially nondiagnostic coronary artery segments, and in over 45% of the cases this improvement was enough to make a previously nondiagnostic vessel segment clinically diagnostic.

Bhagalia, Roshni; Pack, Jed D.; Miller, James V.; Iatrou, Maria [GE Global Research, Niskayuna, New York 12309 (United States); GE Healthcare, Hoboken, New Jersey 07030 (United States)

2012-07-15T23:59:59.000Z

371

Estimation of Rectal Dose Using Daily Megavoltage Cone-Beam Computed Tomography and Deformable Image Registration  

SciTech Connect

Purpose: The actual dose delivered to critical organs will differ from the simulated dose because of interfractional organ motion and deformation. Here, we developed a method to estimate the rectal dose in prostate intensity modulated radiation therapy with consideration to interfractional organ motion using daily megavoltage cone-beam computed tomography (MVCBCT). Methods and Materials: Under exemption status from our institutional review board, we retrospectively reviewed 231 series of MVCBCT of 8 patients with prostate cancer. On both planning CT (pCT) and MVCBCT images, the rectal contours were delineated and the CT value within the contours was replaced by the mean CT value within the pelvis, with the addition of 100 Hounsfield units. MVCBCT images were rigidly registered to pCT and then nonrigidly registered using B-Spline deformable image registration (DIR) with Velocity AI software. The concordance between the rectal contours on MVCBCT and pCT was evaluated using the Dice similarity coefficient (DSC). The dose distributions normalized for 1 fraction were also deformed and summed to estimate the actual total dose. Results: The DSC of all treatment fractions of 8 patients was improved from 0.75±0.04 (mean ±SD) to 0.90 ±0.02 by DIR. Six patients showed a decrease of the generalized equivalent uniform dose (gEUD) from total dose compared with treatment plans. Although the rectal volume of each treatment fraction did not show any correlation with the change in gEUD (R{sup 2}=0.18±0.13), the displacement of the center of gravity of rectal contours in the anterior-posterior (AP) direction showed an intermediate relationship (R{sup 2}=0.61±0.16). Conclusion: We developed a method for evaluation of rectal dose using DIR and MVCBCT images and showed the necessity of DIR for the evaluation of total dose. Displacement of the rectum in the AP direction showed a greater effect on the change in rectal dose compared with the rectal volume.

Akino, Yuichi, E-mail: akino@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Department of Radiology, Osaka University Hospital, Suita, Osaka (Japan); Yoshioka, Yasuo [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Fukuda, Shoichi [Department of Radiation Oncology, Osaka General Medical Center, Osaka (Japan); Maruoka, Shintaroh [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Takahashi, Yutaka [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Department of Radiation Oncology, University of Minnesota, Minneapolis, Minnesota (United States); Yagi, Masashi [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Mizuno, Hirokazu [Department of Radiology, Osaka University Hospital, Suita, Osaka (Japan); Isohashi, Fumiaki [Oncology Center, Osaka University Hospital, Suita, Osaka (Japan); Ogawa, Kazuhiko [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan)

2013-11-01T23:59:59.000Z

372

(/sup 11/C)clorgyline and (/sup 11/C)-L-deprenyl and their use in measuring functional monoamine oxidase activity in the brain using positron emission tomography  

DOE Patents (OSTI)

This invention involves a new strategy for imaging the activity of the enzyme monoamine oxidase in the living body by using /sup 11/C-labeled enzyme inhibitors which bind irreversibly to an enzyme as a result of catalysis. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

1986-04-17T23:59:59.000Z

373

WHOLE CELL TOMOGRAPHY/MOLECULAR BIOLOGY/STRUCTURAL BIOLOGY: Affordable x-ray microscopy with nanoscale resolution  

SciTech Connect

Biological research spans 10 orders of magnitude from angstroms to meters. While electron microscopy can reveal structural details at most of these spatial length scales, transmission electron tomography only reliably reconstructs three-dimensional (3-D) volumes of cellular material with a spatial resolution between 1-5 nm from samples less than 500 nm thick1. Most biological cells are 2-30 times thicker than this threshold, which means that a cell must be cut into consecutive slices with each slice reconstructed individually in order to approximate the contextual information of the entire cell. Fortunately, due to a larger penetration depth2, X-ray computed tomography bypasses the need to physically section a cell and enables imaging of intact cells and tissues on the micrometer or larger scale with tens to hundreds of nanometer spatial resolution. While the technique of soft x-ray microscopy has been extensively developed in synchrotron facilities, advancements in laboratory x-ray source designs now increase its accessibility by supporting commercial systems suitable for a standard laboratory. In this paper, we highlight a new commercial compact cryogenic soft x-ray microscope designed for a standard laboratory setting and explore its capabilities for mesoscopic investigations of intact prokaryotic and eukaryotic cells.

Evans, James E.; Blackborow, Paul; Horne, Stephen J.; Gelb, Jeff

2013-03-01T23:59:59.000Z

374

Three-dimensional imaging of copper pillars using x-ray tomography within a scanning electron microscope: A simulation study based on synchrotron data  

SciTech Connect

While microelectronic devices are frequently characterized with surface-sensitive techniques having nanometer resolution, interconnections used in 3D integration require 3D imaging with high penetration depth and deep sub-micrometer spatial resolution. X-ray tomography is well adapted to this situation. In this context, the purpose of this study is to assess a versatile and turn-key tomographic system allowing for 3D x-ray nanotomography of copper pillars. The tomography tool uses the thin electron beam of a scanning electron microscope (SEM) to provoke x-ray emission from specific metallic targets. Then, radiographs are recorded while the sample rotates in a conventional cone beam tomography scheme that ends up with 3D reconstructions of the pillar. Starting from copper pillars data, collected at the European Synchrotron Radiation Facility, we build a 3D numerical model of a copper pillar, paying particular attention to intermetallics. This model is then used to simulate physical radiographs of the pillar using the geometry of the SEM-hosted x-ray tomography system. Eventually, data are reconstructed and it is shown that the system makes it possible the quantification of 3D intermetallics volume in copper pillars. The paper also includes a prospective discussion about resolution issues.

Martin, N.; Bertheau, J.; Charbonnier, J.; Hugonnard, P.; Lorut, F. [ST Microelectronics, 850 Rue Jean Monnet, 38920 Crolles (France); Bleuet, P.; Tabary, J. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Laloum, D. [ST Microelectronics, 850 Rue Jean Monnet, 38920 Crolles (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

2013-02-15T23:59:59.000Z

375

Measured dose rate constant from oncology patients administered 18F for positron emission tomography  

SciTech Connect

Purpose: Patient exposure rate measurements verify published patient dose rate data and characterize dose rates near 2-18-fluorodeoxyglucose ({sup 18}F-FDG) patients. A specific dose rate constant based on patient exposure rate measurements is a convenient quantity that can be applied to the desired distance, injection activity, and time postinjection to obtain an accurate calculation of cumulative external radiation dose. This study reports exposure rates measured at various locations near positron emission tomography (PET) {sup 18}F-FDG patients prior to PET scanning. These measurements are normalized for the amount of administered activity, measurement distance, and time postinjection and are compared with other published data. Methods: Exposure rates were measured using a calibrated ionization chamber at various body locations from 152 adult oncology patients postvoid after a mean uptake time of 76 min following injection with a mean activity of 490 MBq {sup 18}F-FDG. Data were obtained at nine measurement locations for each patient: three near the head, four near the chest, and two near the feet. Results: On contact with, 30 cm superior to and 30 cm lateral to the head, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.482 (0.511), 0.135 (0.155), and 0.193 (0.223) {mu}Sv/MBq h, respectively. On contact with, 30 cm anterior to, 30 cm lateral to and 1 m anterior to the chest, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.623 (0.709), 0.254 (0.283), 0.190 (0.218), and 0.067 (0.081) {mu}Sv/MBq h respectively. 30 cm inferior and 30 cm lateral to the feet, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.024 (0.022) and 0.039 (0.044) {mu}Sv/MBq h, respectively. Conclusions: The measurements for this study support the use of 0.092 {mu}Sv m{sup 2}/MBq h as a reasonable representation of the dose rate anterior from the chest of patients immediately following injection. This value can then be reliably scaled to the desired time and distance for planning and staff dose evaluation purposes. At distances closer than 1 m, a distance-specific dose rate constant of 0.367 {mu}Sv/MBq h at 30 cm is recommended for accurate calculations. An accurate patient-specific dose rate constant that accounts for patient-specific variables (e.g., distribution and attenuation) will allow an accurate evaluation of the dose rate from a patient injected with an isotope rather than simply utilizing a physical constant.

Quinn, Brian; Holahan, Brian; Aime, Jean; Humm, John; St Germain, Jean; Dauer, Lawrence T. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States) and Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States) and Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States)

2012-10-15T23:59:59.000Z

376

GPD physics with polarized muon beams at COMPASS-II  

SciTech Connect

A major part of the future COMPASS program is dedicated to the investigation of the nucleon structure through Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP). COMPASS will measure DVCS and DVMP reactions with a high intensity muon beam of 160 GeV and a 2.5 m-long liquid hydrogen target surrounded by a new TOF system. The availability of muon beams with high energy and opposite charge and polarization will allow to access the Compton form factor related to the dominant GPD H and to study the x{sub B}-dependence of the t-slope of the pure DVCS cross section and to study nucleon tomography. Projections on the achievable accuracies and preliminary results of pilot measurements will be presented.

Ferrero, Andrea [CEA-Saclay, DSM/Irfu/SpHN, 91191 Gif-sur-Yvette (France); Collaboration: COMPASS Collaboration

2013-04-15T23:59:59.000Z

377

Stability of nanoclusters in 14YWT oxide dispersion strengthened steel under heavy ion-irradiation by atom probe tomography  

SciTech Connect

14YWT oxide dispersion strengthened (ODS) ferritic steel was irradiated with of 5 MeV Ni2+ ions, at 300 C, 450 C, and 600 C to a damage level of 100 dpa. The stability of Ti–Y–O nanoclusters was investigated by applying atom probe tomography (APT) in voltage mode, of the samples before and after irradiations. The average size and number density of the nanoclusters was determined using the maximum separation method. These techniques allowed for the imaging of nanoclusters to sizes well below the resolution limit of conventional transmission electron microscopy techniques. The most significant changes were observed for samples irradiated at 300 C where the size (average Guinier radius) and number density of nanoclusters were observed to decrease from 1.1 nm to 0.8 nm and 12 1023 to 3.6 1023, respectively. In this study, the nanoclusters are more stable at higher temperature.

Jianchao He; Farong Wan; Kumar Sridharan; Todd R. Allen; A. Certain; V. Shutthanandan; Y.Q. Wu

2014-12-01T23:59:59.000Z

378

New Method of Assessing Absolute Permeability of Natural Methane Hydrate Sediments by Microfocus X-ray Computed Tomography  

Science Journals Connector (OSTI)

The structure of natural-gas hydrate sediments was studied using a microfocus X-ray computed-tomography (CT) system. The free-gas spaces, sand particles, and hydrates or ices were identified from the obtained three-dimensional (3-D) images. We used CT data to analyze a continuous pore, which allows gas and water flow. The absolute permeability of sediment samples correlated well with horizontal-channel density in terms of direction. The grain-size distribution in sediment samples depended on the spread of flow channels. The average area and length of a channel evidently have little effect on absolute permeability. We determined that absolute permeability increased with the ratio of horizontal- to vertical-channel numbers. It was clear that the number ratio of the horizontal to vertical channels is a predominant factor that determines absolute permeability in similar porosity ranges. These results indicate that the pore network in sediments can be useful for assessing permeability.

Yusuke Jin; Junko Hayashi; Jiro Nagao; Kiyofumi Suzuki; Hideki Minagawa; Takao Ebinuma; Hideo Narita

2007-01-01T23:59:59.000Z

379

Spatial modeling of the 3D morphology of hybrid polymer-ZnO solar cells, based on electron tomography data  

E-Print Network (OSTI)

A spatial stochastic model is developed which describes the 3D nanomorphology of composite materials, being blends of two different (organic and inorganic) solid phases. Such materials are used, for example, in photoactive layers of hybrid polymer zinc oxide solar cells. The model is based on ideas from stochastic geometry and spatial statistics. Its parameters are fitted to image data gained by electron tomography (ET), where adaptive thresholding and stochastic segmentation have been used to represent morphological features of the considered ET data by unions of overlapping spheres. Their midpoints are modeled by a stack of 2D point processes with a suitably chosen correlation structure, whereas a moving-average procedure is used to add the radii of spheres. The model is validated by comparing physically relevant characteristics of real and simulated data, like the efficiency of exciton quenching, which is important for the generation of charges and their transport toward the electrodes.

O. Stenzel; V. Schmidt; H. Hassfeld; R. Thiedmann; L. J. A. Koster; S. D. Oosterhout; S. S. van Bavel; M. M. Wienk; J. Loos; R. A. J. Janssen

2011-11-22T23:59:59.000Z

380

Accounting for baryonic effects in cosmic shear tomography: Determining a minimal set of nuisance parameters using PCA  

E-Print Network (OSTI)

Systematic uncertainties that have been subdominant in past large-scale structure (LSS) surveys are likely to exceed statistical uncertainties of current and future LSS data sets, potentially limiting the extraction of cosmological information. Here we present a general framework (PCA marginalization) to consistently incorporate systematic effects into a likelihood analysis. This technique naturally accounts for degeneracies between nuisance parameters and can substantially reduce the dimension of the parameter space that needs to be sampled. As a practical application, we apply PCA marginalization to account for baryonic physics as an uncertainty in cosmic shear tomography. Specifically, we use CosmoLike to run simulated likelihood analyses on three independent sets of numerical simulations, each covering a wide range of baryonic scenarios differing in cooling, star formation, and feedback mechanisms. We simulate a Stage III (Dark Energy Survey) and Stage IV (Large Synoptic Survey Telescope/Euclid) survey an...

Eifler, Tim; Dodelson, Scott; Zentner, Andrew; Hearin, Andrew; Gnedin, Nickolay

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography muon tomography" from the National Library of EnergyBeta (NLEBeta).
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381

Clinical Application of In-Room Positron Emission Tomography for In Vivo Treatment Monitoring in Proton Radiation Therapy  

SciTech Connect

Purpose: The purpose of this study is to evaluate the potential of using in-room positron emission tomography (PET) for treatment verification in proton therapy and for deriving suitable PET scan times. Methods and Materials: Nine patients undergoing passive scattering proton therapy underwent scanning immediately after treatment with an in-room PET scanner. The scanner was positioned next to the treatment head after treatment. The Monte Carlo (MC) method was used to reproduce PET activities for each patient. To assess the proton beam range uncertainty, we designed a novel concept in which the measured PET activity surface distal to the target at the end of range was compared with MC predictions. The repositioning of patients for the PET scan took, on average, approximately 2 minutes. The PET images were reconstructed considering varying scan times to test the scan time dependency of the method. Results: The measured PET images show overall good spatial correlations with MC predictions. Some discrepancies could be attributed to uncertainties in the local elemental composition and biological washout. For 8 patients treated with a single field, the average range differences between PET measurements and computed tomography (CT) image-based MC results were <5 mm (<3 mm for 6 of 8 patients) and root-mean-square deviations were 4 to 11 mm with PET-CT image co-registration errors of approximately 2 mm. Our results also show that a short-length PET scan of 5 minutes can yield results similar to those of a 20-minute PET scan. Conclusions: Our first clinical trials in 9 patients using an in-room PET system demonstrated its potential for in vivo treatment monitoring in proton therapy. For a quantitative range prediction with arbitrary shape of target volume, we suggest using the distal PET activity surface.

Min, Chul Hee [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)] [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Zhu, Xuping [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States)] [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Winey, Brian A. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)] [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Grogg, Kira [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States)] [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Testa, Mauro [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)] [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); El Fakhri, Georges [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States)] [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Bortfeld, Thomas R.; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)] [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Shih, Helen A., E-mail: hshih@partners.org [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)

2013-05-01T23:59:59.000Z

382

Lab grants Decision Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

muon tomography, a LANL-developed technology. Muon tomography uses naturally occurring cosmic-ray muons, a type of subatomic particle, to detect and identify concealed...

383

Lab grants Decision Sciences Corporation exclusive commercial...  

NLE Websites -- All DOE Office Websites (Extended Search)

exclusive commercial license for muon tomography Muon tomography uses naturally occurring cosmic-ray muons to detect and identify concealed nuclear threat materials based on...

384

Impact of the number of registration points for replacement of three-dimensional computed tomography images in dental areas using three-dimensional light-scanned images of dental models  

Science Journals Connector (OSTI)

The aim of this study was to investigate the accuracy and reliability of registration methods for replacing dental areas of three-dimensional (3D) computed tomography (CT) images with 3D light-scanned dental i...

Young-Su Choi; Moon-Key Kim; Jae-Won Lee; Sang-Hoon Kang

2014-01-01T23:59:59.000Z

385

Attenuation Tomography of Northern California and the Yellow Sea / Korean Peninsula from Coda-source Normalized and Direct Lg Amplitudes  

SciTech Connect

Inversions for regional attenuation (1/Q) of Lg are performed in two different regions. The path attenuation component of the Lg spectrum is isolated using the coda-source normalization method, which corrects the Lg spectral amplitude for the source using the stable, coda-derived source spectra. Tomographic images of Northern California agree well with one-dimensional (1-D) Lg Q estimated from five different methods. We note there is some tendency for tomographic smoothing to increase Q relative to targeted 1-D methods. For example in the San Francisco Bay Area, which contains high attenuation relative to the rest of it's region, Q is over-estimated by {approx}30. Coda-source normalized attenuation tomography is also carried out for the Yellow Sea/Korean Peninsula (YSKP) where output parameters (site, source, and path terms) are compared with those from the amplitude tomography method of Phillips et al. (2005) as well as a new method that ties the source term to the MDAC formulation (Walter and Taylor, 2001). The source terms show similar scatter between coda-source corrected and MDAC source perturbation methods, whereas the amplitude method has the greatest correlation with estimated true source magnitude. The coda-source better represents the source spectra compared to the estimated magnitude and could be the cause of the scatter. The similarity in the source terms between the coda-source and MDAC-linked methods shows that the latter method may approximate the effect of the former, and therefore could be useful in regions without coda-derived sources. The site terms from the MDAC-linked method correlate slightly with global Vs30 measurements. While the coda-source and amplitude ratio methods do not correlate with Vs30 measurements, they do correlate with one another, which provides confidence that the two methods are consistent. The path Q{sup -1} values are very similar between the coda-source and amplitude ratio methods except for small differences in the Da-xin-anling Mountains, in the northern YSKP. However there is one large difference between the MDAC-linked method and the others in the region near stations TJN and INCN, which point to site-effect as the cause for the difference.

Ford, S R; Dreger, D S; Phillips, W S; Walter, W R; Mayeda, K; Malagnini, L

2008-07-16T23:59:59.000Z

386

An application of Crosswell Tomography using a hydrophone receiver array and airgun source to monitor steam migration in an unconsolidated, heavy-oil sandstone, West Coalinga Field, California  

SciTech Connect

This crosswell tomography field trial demonstrates the viability and cost- reducing benefits of a hydrophone receiver array and airgun source for monitoring steam (heat) migration within an unconsolidated, heavy-oil sandstone. This project represents one of the first applications of hydrophone receivers in such an environment. Data quality from the hydrophone array proved more than adequate for P-wave tomography while costs were reduced dramatically from estimates using a clamped geophone array. Additionally, the resolution provided by the capture of travel-time data from interwell areas offered a distinct advantage over conventional monitoring techniques limited to observation wells. Two crosswell surveys were conducted in the vicinity of a new, infill steam injector. The purpose was to monitor steam migration within an 80-foot thick, sandstone interval by detecting the heat-induced velocity decrease between the first survey, conducted just before steam injection, and the second survey conducted approximately three months later. Difference plots of the two surveys clearly define regions of significant temperature change and contact temperature logs corroborate the zone of peak change. The crosswell tomography data and the inferred steam migration characteristics immediately altered an operational strategy for the drive and were later a factor in the abandonment of continuous steam injection.

Blevens, D.M. (Chevron USA Production Co., Bakersfield, CA (United States)); Fairborn, J.W. (Wellseismic Computing Services, Balboa, CA (United States))

1996-01-01T23:59:59.000Z

387

An application of Crosswell Tomography using a hydrophone receiver array and airgun source to monitor steam migration in an unconsolidated, heavy-oil sandstone, West Coalinga Field, California  

SciTech Connect

This crosswell tomography field trial demonstrates the viability and cost- reducing benefits of a hydrophone receiver array and airgun source for monitoring steam (heat) migration within an unconsolidated, heavy-oil sandstone. This project represents one of the first applications of hydrophone receivers in such an environment. Data quality from the hydrophone array proved more than adequate for P-wave tomography while costs were reduced dramatically from estimates using a clamped geophone array. Additionally, the resolution provided by the capture of travel-time data from interwell areas offered a distinct advantage over conventional monitoring techniques limited to observation wells. Two crosswell surveys were conducted in the vicinity of a new, infill steam injector. The purpose was to monitor steam migration within an 80-foot thick, sandstone interval by detecting the heat-induced velocity decrease between the first survey, conducted just before steam injection, and the second survey conducted approximately three months later. Difference plots of the two surveys clearly define regions of significant temperature change and contact temperature logs corroborate the zone of peak change. The crosswell tomography data and the inferred steam migration characteristics immediately altered an operational strategy for the drive and were later a factor in the abandonment of continuous steam injection.

Blevens, D.M. [Chevron USA Production Co., Bakersfield, CA (United States); Fairborn, J.W. [Wellseismic Computing Services, Balboa, CA (United States)

1996-12-31T23:59:59.000Z

388

Laboratory-Based Cryogenic Soft X-ray Tomography with Correlative Cryo-Light and Electron Microscopy  

SciTech Connect

Here we present a novel laboratory-based cryogenic soft X-ray microscope for whole cell tomography of frozen hydrated samples. We demonstrate the capabilities of this compact cryogenic microscope by visualizing internal sub-cellular structures of Saccharomyces cerevisiae cells. The microscope is shown to achieve better than 50 nm spatial resolution with a Siemens star test sample. For whole biological cells, the microscope can image specimens up to 5 micrometers thick. Structures as small as 90 nm can be detected in tomographic reconstructions at roughly 70 nm spatial resolution following a low cumulative radiation dose of only 7.2 MGy. Furthermore, the design of the specimen chamber utilizes a standard sample support that permits multimodal correlative imaging of the exact same unstained yeast cell via cryo-fluorescence light microscopy, cryo-soft x-ray microscopy and cryo-transmission electron microscopy. This completely laboratory-based cryogenic soft x-ray microscope will therefore enable greater access to three-dimensional ultrastructure determination of biological whole cells without chemical fixation or physical sectioning.

Carlson, David B.; Gelb, Jeff; Palshin, Vadim; Evans, James E.

2013-02-01T23:59:59.000Z

389

Quantum state tomography of large nuclear spins in a semiconductor quantum well: Robustness against errors as quantified by condition numbers  

E-Print Network (OSTI)

We discuss methods of quantum state tomography for solid-state systems with a large nuclear spin $I=3/2$ in nanometer-scale semiconductors devices based on a quantum well. Due to quadrupolar interactions, the Zeeman levels of these nuclear-spin devices become nonequidistant, forming a controllable four-level quantum system (known as quartit or ququart). The occupation of these levels can be selectively and coherently manipulated by multiphoton transitions using the techniques of nuclear magnetic resonance (NMR) [Yusa et al., Nature (London) 434, 101 (2005)]. These methods are based on an unconventional approach to NMR, where the longitudinal magnetization $M_z$ is directly measured. This is in contrast to the standard NMR experiments and tomographic methods, where the transverse magnetization $M_{xy}$ is detected. The robustness against errors in the measured data is analyzed by using condition numbers. We propose several methods with optimized sets of rotations. The optimization is applied to decrease the number of NMR readouts and to improve the robustness against errors, as quantified by condition numbers. An example of state reconstruction, using Monte Carlo methods, is presented. Tomographic methods for quadrupolar nuclei with higher-spin numbers (including $I=7/2$) are also described.

Adam Miranowicz; Sahin K. Ozdemir; Jiri Bajer; Go Yusa; Nobuyuki Imoto; Yoshiro Hirayama; Franco Nori

2014-10-09T23:59:59.000Z

390

Comparison of Computed Tomography and Cineangiography in the Demonstration of Central Pulmonary Arteries in Cyanotic Congenital Heart Disease  

SciTech Connect

Purpose: To assess the diagnostic accuracy of contrast-enhanced computed tomography (CT) for central pulmonary artery pathology in patients with cyanotic congenital heart disease (CCHD) and right ventricular outflow obstruction. Methods: We compared contrast-enhanced CT and cine pulmonary arteriography in 24 patients with CCHD to assess central pulmonary arteries including the confluence. Both investigations were interpreted by a cardiac radiologist in a double-blinded manner at an interval of 3 weeks. Angiography was used as the gold standard for comparison. Results: The sensitivity for visualization of main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), and confluence on CT was 94%, 100%, 92.8%, and 92.8%, respectively. Diagnostic specificity for the same entities was 28.5%, 100%, 80%, and 50%, respectively. The positive predictive value for each was 76.2%, 100%, 94.1%, and 72.2%, respectively. The low specificity of CT in the evaluation of the MPA and the confluence is perhaps due to distorted right ventricular outflow anatomy in CCHD. Large aortopulmonary collaterals in this region were mistaken for the MPA in some patients with pulmonary atresia. Conclusion: CT is a useful, relatively noninvasive, imaging technique for the central pulmonary arteries in selected patients. It can supplement diagnostic information from angiography but cannot replace it. LPA demonstration on axial images alone is inadequate.

Taneja, Karuna; Sharma, Sanjiv [Department of Cardiovascular Radiology, C.T. Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110 029 (India); Kumar, Krishan [Department of Cardiology, C.T. Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110 029 (India); Rajani, Mira [Department of Cardiovascular Radiology, C.T. Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110 029 (India)

1996-03-15T23:59:59.000Z

391

X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand  

SciTech Connect

We used X-ray computed tomography (CT) to image and quantify the effect of a heterogeneous sand grain-size distribution on the formation and dissociation of methane hydrate, as well as the effect on water flow through the heterogeneous hydrate-bearing sand. A 28 cm long sand column was packed with several segments having vertical and horizontal layers with sands of different grain-size distributions. During the hydrate formation, water redistribution occurred. Observations of water flow through the hydrate-bearing sands showed that water was imbibed more readily into the fine sand, and that higher hydrate saturation increased water imbibition in the coarse sand due to increased capillary strength. Hydrate dissociation induced by depressurization resulted in different flow patterns with the different grain sizes and hydrate saturations, but the relationships between dissociation rates and the grain sizes could not be identified using the CT images. The formation, presence, and dissociation of hydrate in the pore space dramatically impact water saturation and flow in the system.

Seol, Yongkoo; Kneafsey, Timothy J.

2009-06-01T23:59:59.000Z

392

Spatial variation of void ratio and shear band thickness in sand using X-ray computed tomography  

SciTech Connect

A detailed study of spatial variation of void ratio and shear band thickness measurements is presented in this paper. A prismatic sand specimen that initially measured 57{center_dot}4 mm wide x 120{center_dot}5 mm long x 182{center_dot}1 mm high was sheared under plane-strain (biaxial) loading conditions. The specimen was prepared at a relative density of 79% using F-75 Ottawa sand. X-ray computed tomography was used to scan the specimen before shearing and after the onset of the shear band. The specimen failed through a single shear band with an inclination angle of 65{center_dot}6{sup o} measured from the direction of the minor principal stress. Computer algorithms were developed to calibrate CT images and quantify void ratio (e) variation within the specimen. CT data analysis revealed cross-sectional spatial variation in void ratio where density is higher in regions close to the edges of the specimen due to membrane effects and confining pressure with no significant variation in void ratio in the axial direction (top to bottom) before shearing. The shear band was easily identified from the CT images, and analysis of void ratio showed a noticeable jump in void ratio profile across the shear band. A detailed statistical summary of the thickness of the shear band and variation of void ratio across the shear band is presented and discussed.

Alshibli, K.A.; Hasan, A. (LSU)

2008-05-01T23:59:59.000Z

393

Vocal tract changes caused by phonation into a tube: A case study using computer tomography and finite-element modeling  

Science Journals Connector (OSTI)

Phonation into a glass tube is a voice training and therapy method that leads to beneficial effects in voice production. It has not been known however what changes occur in the vocal tract during and after the phonation into a tube. This pilot study examined the vocal tract shape in a female subject before during and after phonation into a tube using computer tomography(CT). Three-dimensional finite-elementmodels (FEMs) of the vocal tract were derived from the CTimages and used to study changes in vocal tract input impedance. When phonating on vowel [a:] the data showed tightened velopharyngeal closure and enlarged cross-sectional areas of the oropharyngeal and oral cavities during and after the tube-phonation. FEM calculations revealed an increased input inertance of the vocal tract and an increased acoustic energy radiated out of the vocal tract after the tube-phonation. The results indicate that the phonation into a tube causes changes in the vocal tract which remain also when the tube is removed. These effects may help improving voice production in patients and voice professionals.

Tomáš Vampola; Anne-Maria Laukkanen; Jaromír Horá?ek; Jan G. Švec

2011-01-01T23:59:59.000Z

394

Muon systems  

SciTech Connect

The designs of both the GEM and SDC muon systems an the technological choices are reviewed. In particular, the chamber options for the detectors are discussed.

Bensinger, J.

1991-10-01T23:59:59.000Z

395

Impact of Four-Dimensional Computed Tomography Pulmonary Ventilation Imaging-Based Functional Avoidance for Lung Cancer Radiotherapy  

SciTech Connect

Purpose: To quantify the dosimetric impact of four-dimensional computed tomography (4D-CT) pulmonary ventilation imaging-based functional treatment planning that avoids high-functional lung regions. Methods and Materials: 4D-CT ventilation images were created from 15 non-small-cell lung cancer patients using deformable image registration and quantitative analysis of the resultant displacement vector field. For each patient, anatomic and functional plans were created for intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). Consistent beam angles and dose-volume constraints were used for all cases. The plans with Radiation Therapy Oncology Group (RTOG) 0617-defined major deviations were modified until clinically acceptable. Functional planning spared the high-functional lung, and anatomic planning treated the lungs as uniformly functional. We quantified the impact of functional planning compared with anatomic planning using the two- or one-tailed t test. Results: Functional planning led to significant reductions in the high-functional lung dose, without significantly increasing other critical organ doses, but at the expense of significantly degraded the planning target volume (PTV) conformity and homogeneity. The average reduction in the high-functional lung mean dose was 1.8 Gy for IMRT (p < .001) and 2.0 Gy for VMAT (p < .001). Significantly larger changes occurred in the metrics for patients with a larger amount of high-functional lung adjacent to the PTV. Conclusion: The results of the present study have demonstrated the impact of 4D-CT ventilation imaging-based functional planning for IMRT and VMAT for the first time. Our findings indicate the potential of functional planning in lung functional avoidance for both IMRT and VMAT, particularly for patients who have high-functional lung adjacent to the PTV.

Yamamoto, Tokihiro, E-mail: Tokihiro@stanford.ed [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Kabus, Sven; Berg, Jens von; Lorenz, Cristian [Department of Digital Imaging, Philips Research Europe, Hamburg (Germany); Keall, Paul J. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)

2011-01-01T23:59:59.000Z

396

Computed Tomography-Guided High-Dose-Rate Brachytherapy in Hepatocellular Carcinoma: Safety, Efficacy, and Effect on Survival  

SciTech Connect

Purpose: To determine the saftety and efficacy of computed tomography (CT)-guided brachytherapy in hepatocellular carcinoma (HCC). Methods and Materials: A total of 83 patients were recruited, presenting with 140 HCC- lesions. Treatment was performed by CT-guided high-dose-rate (HDR) brachytherapy with an iridium-192 source. The primary endpoint was time to progression; secondary endpoints included local tumor control and overall survival (OS). A matched-pair analysis with patients not receiving brachytherapy was performed. Match criteria included the Cancer of the Liver Italian Program (CLIP) score, alpha-fetoprotein, presence, and extent of multifocal disease. For statistical analysis, Kaplan-Meier and Cox regression were performed. Results: Mean and median cumulative TTP for all patients (n = 75) were 17.7 and 10.4 months. Five local recurrences were observed. The OS after inclusion reached median times of 19.4 months (all patients), 46.3 months (CLIP score, 0), 20.6 months (CLIP score, 1) 12.7 months, (CLIP score, 2), and 8.3 months (CLIP score, {>=}3). The 1- and 3-year OS were 94% and 65% (CLIP score, 0), 69% and 12% (CLIP score, 1), and 48% and 19% (CLIP score, 2), respectively. Nine complications requiring intervention were encountered in 124 interventions. Matched-pair analysis revealed a significantly longer OS for patients undergoing CT-guided brachytherapy. Conclusion: Based on our results the study treatment could be safely performed. The study treatment had a beneficial effect on OS in patients with advanced HCC, with respect to (and depending on) the CLIP score and compared with OS in a historical control group. A high rate of local control was also observed, regardless of applied dose in a range of 15 to 25 Gy.

Mohnike, Konrad; Wieners, Gero; Schwartz, Franziska; Seidensticker, Max; Pech, Maciej; Ruehl, Ricarda [Klinik fuer Radiologie und Nuklearmedizin, Otto von Guericke University, Magdeburg (Germany); Wust, Peter [Klinik fuer Strahlentherapie, Charite Universitaetsmedizin, Berlin (Germany); Lopez-Haenninen, Enrique [Klinik fuer Radiologie und Nuklearmedizin, Martin-Luther-Krankenhaus, Berlin (Germany); Gademann, Guenther; Peters, Nils [Klinik fuer Strahlentherapie, Otto von Guericke University, Magdeburg (Germany); Berg, Thomas [Medizinische Klinik mit Schwerpunkt Hepato-Gastroenterologie, Charite Universitaetsmedizin, Berlin (Germany); Malfertheiner, Peter [Klinik fuer Gastroenterologie und Hepatologie, Otto von Guericke University, Magdeburg (Germany); Ricke, Jens, E-mail: ricke@med.ovgu.d [Klinik fuer Radiologie und Nuklearmedizin, Otto von Guericke University, Magdeburg (Germany)

2010-09-01T23:59:59.000Z

397

Breast Patient Setup Error Assessment: Comparison of Electronic Portal Image Devices and Cone-Beam Computed Tomography Matching Results  

SciTech Connect

Purpose: To quantify the differences in setup errors measured with the cone-beam computed tomography (CBCT) and electronic portal image devices (EPID) in breast cancer patients. Methods and Materials: Repeat CBCT scan were acquired for routine offline setup verification in 20 breast cancer patients. During the CBCT imaging fractions, EPID images of the treatment beams were recorded. Registrations of the bony anatomy for CBCT to planning CT and EPID to digitally reconstructed-radiographs (DRRs) were compared. In addition, similar measurements of an anthropomorphic thorax phantom were acquired. Bland-Altman and linear regression analysis were performed for clinical and phantom registrations. Systematic and random setup errors were quantified for CBCT and EPID-driven correction protocols in the EPID coordinate system (U, V), with V parallel to the cranial-caudal axis and U perpendicular to V and the central beam axis. Results: Bland-Altman analysis of clinical EPID and CBCT registrations yielded 4 to 6-mm limits of agreement, indicating that both methods were not compatible. The EPID-based setup errors were smaller than the CBCT-based setup errors. Phantom measurements showed that CBCT accurately measures setup error whereas EPID underestimates setup errors in the cranial-caudal direction. In the clinical measurements, the residual bony anatomy setup errors after offline CBCT-based corrections were {Sigma}{sub U} = 1.4 mm, {Sigma}{sub V} = 1.7 mm, and {sigma}{sub U} = 2.6 mm, {sigma}{sub V} = 3.1 mm. Residual setup errors of EPID driven corrections corrected for underestimation were estimated at {Sigma}{sub U} = 2.2mm, {Sigma}{sub V} = 3.3 mm, and {sigma}{sub U} = 2.9 mm, {sigma}{sub V} = 2.9 mm. Conclusion: EPID registration underestimated the actual bony anatomy setup error in breast cancer patients by 20% to 50%. Using CBCT decreased setup uncertainties significantly.

Topolnjak, Rajko [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Sonke, Jan-Jakob, E-mail: j.sonke@nki.n [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Nijkamp, Jasper; Rasch, Coen; Minkema, Danny; Remeijer, Peter; Vliet-Vroegindeweij, Corine van [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

2010-11-15T23:59:59.000Z

398

Frequency and Clinical Significance of Previously Undetected Incidental Findings Detected on Computed Tomography Simulation Scans for Breast Cancer Patients  

SciTech Connect

Purpose: To determine the frequency and clinical significance of previously undetected incidental findings found on computed tomography (CT) simulation images for breast cancer patients. Methods and Materials: All CT simulation images were first interpreted prospectively by radiation oncologists and then double-checked by diagnostic radiologists. The official reports of CT simulation images for 881 consecutive postoperative breast cancer patients from 2009 to 2010 were retrospectively reviewed. Potentially important incidental findings (PIIFs) were defined as any previously undetected benign or malignancy-related findings requiring further medical follow-up or investigation. For all patients in whom a PIIF was detected, we reviewed the clinical records to determine the clinical significance of the PIIF. If the findings from the additional studies prompted by a PIIF required a change in management, the PIIF was also recorded as a clinically important incidental finding (CIIF). Results: There were a total of 57 (6%) PIIFs. The 57 patients in whom a PIIF was detected were followed for a median of 17 months (range, 3-26). Six cases of CIIFs (0.7% of total) were detected. Of the six CIIFs, three (50%) cases had not been noted by the radiation oncologist until the diagnostic radiologist detected the finding. On multivariate analysis, previous CT examination was an independent predictor for PIIF (p = 0.04). Patients who had not previously received chest CT examinations within 1 year had a statistically significantly higher risk of PIIF than those who had received CT examinations within 6 months (odds ratio, 3.54; 95% confidence interval, 1.32-9.50; p = 0.01). Conclusions: The rate of incidental findings prompting a change in management was low. However, radiation oncologists appear to have some difficulty in detecting incidental findings that require a change in management. Considering cost, it may be reasonable that routine interpretations are given to those who have not received previous chest CT examinations within 1 year.

Nakamura, Naoki, E-mail: naokinak@luke.or.jp [Department of Radiation Oncology, St. Luke's International Hospital, Tokyo (Japan)] [Department of Radiation Oncology, St. Luke's International Hospital, Tokyo (Japan); Tsunoda, Hiroko [Department of Radiology, St. Luke's International Hospital, Tokyo (Japan)] [Department of Radiology, St. Luke's International Hospital, Tokyo (Japan); Takahashi, Osamu [Division of General Internal Medicine, Department of Medicine, St. Luke's International Hospital, Tokyo (Japan)] [Division of General Internal Medicine, Department of Medicine, St. Luke's International Hospital, Tokyo (Japan); Kikuchi, Mari; Honda, Satoshi [Department of Radiology, St. Luke's International Hospital, Tokyo (Japan)] [Department of Radiology, St. Luke's International Hospital, Tokyo (Japan); Shikama, Naoto [Department of Radiation Oncology, Saitama Medical University International Medical Center, Hidaka (Japan)] [Department of Radiation Oncology, Saitama Medical University International Medical Center, Hidaka (Japan); Akahane, Keiko; Sekiguchi, Kenji [Department of Radiation Oncology, St. Luke's International Hospital, Tokyo (Japan)] [Department of Radiation Oncology, St. Luke's International Hospital, Tokyo (Japan)

2012-11-01T23:59:59.000Z

399

Integration and evaluation of a needle-positioning robot with volumetric microcomputed tomography image guidance for small animal stereotactic interventions  

SciTech Connect

Purpose: Preclinical research protocols often require insertion of needles to specific targets within small animal brains. To target biologically relevant locations in rodent brains more effectively, a robotic device has been developed that is capable of positioning a needle along oblique trajectories through a single burr hole in the skull under volumetric microcomputed tomography (micro-CT) guidance. Methods: An x-ray compatible stereotactic frame secures the head throughout the procedure using a bite bar, nose clamp, and ear bars. CT-to-robot registration enables structures identified in the image to be mapped to physical coordinates in the brain. Registration is accomplished by injecting a barium sulfate contrast agent as the robot withdraws the needle from predefined points in a phantom. Registration accuracy is affected by the robot-positioning error and is assessed by measuring the surface registration error for the fiducial and target needle tracks (FRE and TRE). This system was demonstrated in situ by injecting 200 {mu}m tungsten beads into rat brains along oblique trajectories through a single burr hole on the top of the skull under micro-CT image guidance. Postintervention micro-CT images of each skull were registered with preintervention high-field magnetic resonance images of the brain to infer the anatomical locations of the beads. Results: Registration using four fiducial needle tracks and one target track produced a FRE and a TRE of 96 and 210 {mu}m, respectively. Evaluation with tissue-mimicking gelatin phantoms showed that locations could be targeted with a mean error of 154{+-}113 {mu}m. Conclusions: The integration of a robotic needle-positioning device with volumetric micro-CT image guidance should increase the accuracy and reduce the invasiveness of stereotactic needle interventions in small animals.

Waspe, Adam C.; McErlain, David D.; Pitelka, Vasek; Holdsworth, David W.; Lacefield, James C.; Fenster, Aaron [Biomedical Engineering Graduate Program and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Department of Medical Biophysics and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Biomedical Engineering Graduate Program, Department of Medical Biophysics, Department of Medical Imaging, Department of Surgery, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Biomedical Engineering Graduate Program, Department of Electrical and Computer Engineering, Department of Medical Biophysics, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Biomedical Engineering Graduate Program, Department of Medical Biophysics, Department of Medical Imaging, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada)

2010-04-15T23:59:59.000Z

400

Reduced Kilovoltage in Computed Tomography–Guided Intervention in a Community Hospital: Effect on the Radiation Dose  

Science Journals Connector (OSTI)

AbstractPurpose The purpose of this study was to determine whether low-kilovoltage (80 or 100 kV) computed tomography (CT)-guided interventions performed in a community-based hospital are feasible and to compare radiation exposure incurred with conventional 120 kV potential. Materials and Methods Effective doses (ED) received by patients who underwent CT-guided intervention were analysed before and after a low-dose kilovoltage protocol was instituted in our department. We performed CT-guided procedures of 93 consecutive patients by using conventional 120-kV tube voltage (50 patients) and a low voltage of 80 or 100 kV for the remainder of this cohort. Automatic tube current modulation was enabled to obtain the best image quality. Procedure details were prospectively recorded and included examination site and type, slice width, tube voltage and current, dose length product, volume CT dose index, and size-specific dose estimate. Dose length product was converted to ED to account for radiosensitivity of specific organs. Statistical comparisons with test differences in the ED, volume CT dose index, size-specific dose estimate, and effective diameter (patient size) were made by using the Student t test. Results All but 6 of the procedures performed at 80 kV were successful, for a success rate of 86%. At lower voltages, the ED was significantly (P dose radiation technique by using 80 or 100 kV results in a high technical success rate for pelvic, chest, and abdomen CT-guided interventional procedures, although dramatically decreasing radiation exposure. There was no significant difference in effective diameter (patient size) between the conventional and the low-dose groups, which would suggest that dose reduction was indeed a result of kVp change and not patient size.

Saman Rezazadeh; Steven J. Co; Simon Bicknell

2014-01-01T23:59:59.000Z

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401

Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)  

SciTech Connect

The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO{sub 4}) solution. As a tissue-staining contrast agent, OsO{sub 4} is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO{sub 4} preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE{sup -/-}) mice at 10 {mu}m resolution. The results show that walls of coronary arteries as small as 45 {mu}m in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO{sub 4} and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han (NIH)

2012-05-10T23:59:59.000Z

402

Cardiac C-arm computed tomography using a 3D + time ROI reconstruction method with spatial and temporal regularization  

SciTech Connect

Purpose: Reconstruction of the beating heart in 3D + time in the catheter laboratory using only the available C-arm system would improve diagnosis, guidance, device sizing, and outcome control for intracardiac interventions, e.g., electrophysiology, valvular disease treatment, structural or congenital heart disease. To obtain such a reconstruction, the patient's electrocardiogram (ECG) must be recorded during the acquisition and used in the reconstruction. In this paper, the authors present a 4D reconstruction method aiming to reconstruct the heart from a single sweep 10 s acquisition. Methods: The authors introduce the 4D RecOnstructiOn using Spatial and TEmporal Regularization (short 4D ROOSTER) method, which reconstructs all cardiac phases at once, as a 3D + time volume. The algorithm alternates between a reconstruction step based on conjugate gradient and four regularization steps: enforcing positivity, averaging along time outside a motion mask that contains the heart and vessels, 3D spatial total variation minimization, and 1D temporal total variation minimization. Results: 4D ROOSTER recovers the different temporal representations of a moving Shepp and Logan phantom, and outperforms both ECG-gated simultaneous algebraic reconstruction technique and prior image constrained compressed sensing on a clinical case. It generates 3D + time reconstructions with sharp edges which can be used, for example, to estimate the patient's left ventricular ejection fraction. Conclusions: 4D ROOSTER can be applied for human cardiac C-arm CT, and potentially in other dynamic tomography areas. It can easily be adapted to other problems as regularization is decoupled from projection and back projection.

Mory, Cyril, E-mail: cyril.mory@philips.com [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France) [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France); Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes (France); Auvray, Vincent; Zhang, Bo [Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes (France)] [Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes (France); Grass, Michael; Schäfer, Dirk [Philips Research, Röntgenstrasse 24–26, D-22335 Hamburg (Germany)] [Philips Research, Röntgenstrasse 24–26, D-22335 Hamburg (Germany); Chen, S. James; Carroll, John D. [Department of Medicine, Division of Cardiology, University of Colorado Denver, 12605 East 16th Avenue, Aurora, Colorado 80045 (United States)] [Department of Medicine, Division of Cardiology, University of Colorado Denver, 12605 East 16th Avenue, Aurora, Colorado 80045 (United States); Rit, Simon [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1 (France) [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1 (France); Centre Léon Bérard, 28 rue Laënnec, F-69373 Lyon (France); Peyrin, Françoise [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France) [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France); X-ray Imaging Group, European Synchrotron, Radiation Facility, BP 220, F-38043 Grenoble Cedex (France); Douek, Philippe; Boussel, Loïc [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1 (France) [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1 (France); Hospices Civils de Lyon, 28 Avenue du Doyen Jean Lépine, 69500 Bron (France)

2014-02-15T23:59:59.000Z

403

Carbon monoxide line emission as a CMB foreground: tomography of the star-forming universe with different spectral resolutions  

E-Print Network (OSTI)

The rotational lines of carbon monoxide and the fine structure lines of CII and of the most abundant metals, emitted during the epoch of enhanced star formation in the universe, are redshifted in the frequency channels where the present-day and future CMB experiments are sensitive. We estimate the contribution to the CMB angular power spectrum by the emission in such lines in merging star-forming galaxies. We used the Lacey-Cole approach to characterize the distribution of the merging halos, together with a parametrization for the star formation rate in each of them. Using observational data from a sample of local, low-redshift, and high-redshift objects, we calibrated the luminosity in each line as a function of the star formation rate. We show that the correlation term arising from CO line emission is a significant source of foreground for CMB in a broad range of frequencies (in particular in the 20-60 GHz band) and for 1000tomography of the universe, by probing different redshift slices with varying thickness. (abridged)

Mattia Righi; Carlos Hernandez-Monteagudo; Rashid Sunyaev

2008-07-24T23:59:59.000Z

404

Comparison of Rigid and Adaptive Methods of Propagating Gross Tumor Volume Through Respiratory Phases of Four-Dimensional Computed Tomography Image Data Set  

SciTech Connect

Purpose: To compare three different methods of propagating the gross tumor volume (GTV) through the respiratory phases that constitute a four-dimensional computed tomography image data set. Methods and Materials: Four-dimensional computed tomography data sets of 20 patients who had undergone definitive hypofractionated radiotherapy to the lung were acquired. The GTV regions of interest (ROIs) were manually delineated on each phase of the four-dimensional computed tomography data set. The ROI from the end-expiration phase was propagated to the remaining nine phases of respiration using the following three techniques: (1) rigid-image registration using in-house software, (2) rigid image registration using research software from a commercial radiotherapy planning system vendor, and (3) rigid-image registration followed by deformable adaptation originally intended for organ-at-risk delineation using the same software. The internal GTVs generated from the various propagation methods were compared with the manual internal GTV using the normalized Dice similarity coefficient (DSC) index. Results: The normalized DSC index of 1.01 {+-} 0.06 (SD) for rigid propagation using the in-house software program was identical to the normalized DSC index of 1.01 {+-} 0.06 for rigid propagation achieved with the vendor's research software. Adaptive propagation yielded poorer results, with a normalized DSC index of 0.89 {+-} 0.10 (paired t test, p <0.001). Conclusion: Propagation of the GTV ROIs through the respiratory phases using rigid- body registration is an acceptable method within a 1-mm margin of uncertainty. The adaptive organ-at-risk propagation method was not applicable to propagating GTV ROIs, resulting in an unacceptable reduction of the volume and distortion of the ROIs.

Ezhil, Muthuveni [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)], E-mail: veniezhil@hotmail.com; Choi, Bum; Starkschall, George [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Bucci, M. Kara [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Vedam, Sastry; Balter, Peter [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

2008-05-01T23:59:59.000Z

405

Computed tomography image using sub-terahertz waves generated from a high-T{sub c} superconducting intrinsic Josephson junction oscillator  

SciTech Connect

A computed tomography (CT) imaging system using monochromatic sub-terahertz coherent electromagnetic waves generated from a device constructed from the intrinsic Josephson junctions in a single crystalline mesa structure of the high-T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+?} was developed and tested on three samples: Standing metallic rods supported by styrofoam, a dried plant (heart pea) containing seeds, and a plastic doll inside an egg shell. The images obtained strongly suggest that this CT imaging system may be useful for a variety of practical applications.

Kashiwagi, T., E-mail: kashiwagi@ims.tsukuba.ac.jp; Minami, H.; Kadowaki, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Nakade, K.; Saiwai, Y.; Kitamura, T.; Watanabe, C.; Ishida, K.; Sekimoto, S.; Asanuma, K.; Yasui, T.; Shibano, Y. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Tsujimoto, M. [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Yamamoto, T. [Wide Bandgap Materials Group, Optical and Electronic Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Markovi?, B. [Faculty of Sciences, University of Montenegro, George Washington Str., 81000 Podgorica (Montenegro); Mirkovi?, J. [Faculty of Science, University of Montenegro, and CETI, Put Radomira Ivanovica, 81000 Podgorica (Montenegro); Klemm, R. A. [Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, Florida 32816-2385 (United States)

2014-02-24T23:59:59.000Z

406

Radiolabeling of poly(lactic-co-glycolic acid) (PLGA) nanoparticles with biotinylated F-18 prosthetic groups and imaging of their delivery to the brain with positron emission tomography  

Science Journals Connector (OSTI)

Radiolabeling of poly(lactic-co-glycolic acid) (PLGA) nanoparticles with biotinylated F-18 prosthetic groups and imaging of their delivery to the brain with positron emission tomography ... The attachment of the [18F]NPB4 radioligand to avidin-modified poly(lactic-co-glycolic acid) (PLGA) nanoparticles was tested by using PET imaging of the rat brain to measure the kinetics of convection-enhanced delivery (CED) of nanoparticles of varying size. ... This work thus validates new methods for radiolabeling PEG-biotin derivatives and also provides insight into the fate of nanoparticles that have been infused directly into the brain. ...

Rachael Weiss Sirianni; MingQiang Zheng; Toral Patel; Thomas Schafbauer; Jiangbing Zhou; W. Mark Saltzman; Richard E Carson; Yiyun Henry Huang

2014-10-16T23:59:59.000Z

407

Outcomes of Positron Emission Tomography-Staged Clinical N3 Breast Cancer Treated With Neoadjuvant Chemotherapy, Surgery, and Radiotherapy  

SciTech Connect

Purpose: To evaluate the treatment outcome and efficacy of regional lymph node irradiation after neoadjuvant chemotherapy (NCT) and surgery in positron emission tomography (PET)-positive clinical N3 (cN3) breast cancer patients. Methods and Materials: A total of 55 patients with ipsilateral infraclavicular (ICL), internal mammary (IMN), or supraclavicular (SCL) lymph node involvement in the absence of distant metastases, as revealed by an initial PET scan, were retrospectively analyzed. The clinical nodal stage at diagnosis (2002 AJCC) was cN3a in 14 patients (26%), cN3b in 12 patients (22%), and cN3c in 29 patients (53%). All patients were treated with NCT, followed by mastectomy or breast-conserving surgery and subsequent radiotherapy (RT) with curative intent. Results: At the median follow-up of 38 months (range, 9-80 months), 20 patients (36%) had developed treatment failures, including distant metastases either alone or combined with locoregional recurrences that included one ipsilateral breast recurrence (IBR), six regional failures (RF), and one case of combined IBR and RF. Only 3 patients (5.5%) exhibited treatment failure at the initial PET-positive clinical N3 lymph node. The 5-year locoregional relapse-free survival, disease-free survival (DFS), and overall survival rates were 80%, 60%, and 79%, respectively. RT delivered to PET-positive IMN regions in cN3b patients and at higher doses ({>=}55 Gy) to SCL regions in cN3c patients was not associated with improved 5-year IMN/SCL relapse-free survival or DFS. Conclusion: NCT followed by surgery and RT, including the regional lymph nodes, resulted in excellent locoregional control for patients with PET-positive cN3 breast cancer. The primary treatment failure in this group was due to distant metastasis rather than RF. Neither higher-dose RT directed at PET-positive SCL nodes nor coverage of PET-positive IMN nodes was associated with additional gains in locoregional control or DFS.

Park, Hae Jin [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Shin, Kyung Hwan, E-mail: radiat@ncc.re.kr [Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Cho, Kwan Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Park, In Hae; Lee, Keun Seok; Ro, Jungsil; Jung, So-Youn; Lee, Seeyoun; Kim, Seok Won; Kang, Han-Sung [Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Chie, Eui Kyu; Ha, Sung Whan [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

2011-12-01T23:59:59.000Z

408

Comparison of x ray computed tomography number to proton relative linear stopping power conversion functions using a standard phantom  

SciTech Connect

Purpose: Adequate evaluation of the results from multi-institutional trials involving light ion beam treatments requires consideration of the planning margins applied to both targets and organs at risk. A major uncertainty that affects the size of these margins is the conversion of x ray computed tomography numbers (XCTNs) to relative linear stopping powers (RLSPs). Various facilities engaged in multi-institutional clinical trials involving proton beams have been applying significantly different margins in their patient planning. This study was performed to determine the variance in the conversion functions used at proton facilities in the U.S.A. wishing to participate in National Cancer Institute sponsored clinical trials. Methods: A simplified method of determining the conversion function was developed using a standard phantom containing only water and aluminum. The new method was based on the premise that all scanners have their XCTNs for air and water calibrated daily to constant values but that the XCTNs for high density/high atomic number materials are variable with different scanning conditions. The standard phantom was taken to 10 different proton facilities and scanned with the local protocols resulting in 14 derived conversion functions which were compared to the conversion functions used at the local facilities. Results: For tissues within ±300 XCTN of water, all facility functions produced converted RLSP values within ±6% of the values produced by the standard function and within 8% of the values from any other facility's function. For XCTNs corresponding to lung tissue, converted RLSP values differed by as great as ±8% from the standard and up to 16% from the values of other facilities. For XCTNs corresponding to low-density immobilization foam, the maximum to minimum values differed by as much as 40%. Conclusions: The new method greatly simplifies determination of the conversion function, reduces ambiguity, and in the future could promote standardization between facilities. Although it was not possible from these experiments to determine which conversion function is most appropriate, the variation between facilities suggests that the margins used in some facilities to account for the uncertainty in converting XCTNs to RLSPs may be too small.

Moyers, M. F., E-mail: MFMoyers@roadrunner.com [Shanghai Proton and Heavy Ion Center, Shanghai, China 201321 (China)

2014-06-15T23:59:59.000Z

409

A quality assurance framework for the fully automated and objective evaluation of image quality in cone-beam computed tomography  

SciTech Connect

Purpose: Thousands of cone-beam computed tomography (CBCT) scanners for vascular, maxillofacial, neurological, and body imaging are in clinical use today, but there is no consensus on uniform acceptance and constancy testing for image quality (IQ) and dose yet. The authors developed a quality assurance (QA) framework for fully automated and time-efficient performance evaluation of these systems. In addition, the dependence of objective Fourier-based IQ metrics on direction and position in 3D volumes was investigated for CBCT. Methods: The authors designed a dedicated QA phantom 10 cm in length consisting of five compartments, each with a diameter of 10 cm, and an optional extension ring 16 cm in diameter. A homogeneous section of water-equivalent material allows measuring CT value accuracy, image noise and uniformity, and multidimensional global and local noise power spectra (NPS). For the quantitative determination of 3D high-contrast spatial resolution, the modulation transfer function (MTF) of centrally and peripherally positioned aluminum spheres was computed from edge profiles. Additional in-plane and axial resolution patterns were used to assess resolution qualitatively. The characterization of low-contrast detectability as well as CT value linearity and artifact behavior was tested by utilizing sections with soft-tissue-equivalent and metallic inserts. For an automated QA procedure, a phantom detection algorithm was implemented. All tests used in the dedicated QA program were initially verified in simulation studies and experimentally confirmed on a clinical dental CBCT system. Results: The automated IQ evaluation of volume data sets of the dental CBCT system was achieved with the proposed phantom requiring only one scan for the determination of all desired parameters. Typically, less than 5 min were needed for phantom set-up, scanning, and data analysis. Quantitative evaluation of system performance over time by comparison to previous examinations was also verified. The maximum percentage interscan variation of repeated measurements was less than 4% and 1.7% on average for all investigated quality criteria. The NPS-based image noise differed by less than 5% from the conventional standard deviation approach and spatially selective 10% MTF values were well comparable to subjective results obtained with 3D resolution pattern. Determining only transverse spatial resolution and global noise behavior in the central field of measurement turned out to be insufficient. Conclusions: The proposed framework transfers QA routines employed in conventional CT in an advanced version to CBCT for fully automated and time-efficient evaluation of technical equipment. With the modular phantom design, a routine as well as an expert version for assessing IQ is provided. The QA program can be used for arbitrary CT units to evaluate 3D imaging characteristics automatically.

Steiding, Christian; Kolditz, Daniel; Kalender, Willi A., E-mail: willi.kalender@imp.uni-erlangen.de [Institute of Medical Physics, University of Erlangen-Nürnberg, Henkestraße 91, 91052 Erlangen, Germany and CT Imaging GmbH, 91052 Erlangen (Germany)

2014-03-15T23:59:59.000Z

410

Muon Collider  

SciTech Connect

Parameters are given of muon colliders with center of mass energies of 1.5 and 3 TeV. Pion production is from protons on a mercury target. Capture, decay, and phase rotation yields bunch trains of both muon signs. Six dimensional cooling reduces the emittances until the trains are merged into single bunches, one of each sign. Further cooling in 6 dimensions is then applied, followed by final transverse cooling in 50 T solenoids. After acceleration the muons enter the collider ring. Ongoing R&D is discussed.

Palmer, R.

2009-10-19T23:59:59.000Z

411

Muon Tridents  

Science Journals Connector (OSTI)

Under the assumption that muons are heavy electrons, the total cross section for muon tridents on lead is calculated for 12.0-BeV incident muons including the effect of exchange for identical particles in the final state; various differential cross sections are presented. The positron spectrum for 31.5-MeV electron tridents on copper is also calculated and found to agree with Criegee's experimental results. It is found that the entire effect of statistics is confined to a region of phase space where the two leptons of like charge in the final state have an invariant mass of less than 3.5 times their rest mass.

Michael J. Tannenbaum

1968-03-25T23:59:59.000Z

412

Understanding Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Microscopy and Field Evaporation Simulation  

SciTech Connect

Metal-dielectric composite materials, specifically metal nanoparticles supported on or embedded in metal oxides, are widely used in catalysis. The accurate optimization of such nanostructures warrants the need for detailed three-dimensional characterization. Atom probe tomography is uniquely capable of generating sub-nanometer structural and compositional data with part-per-million mass sensitivity, but there are reconstruction artifacts for composites containing materials with strongly differing fields of evaporation, as for oxide-supported metal nanoparticles. By correlating atom probe tomography with scanning transmission electron microscopy for Au nanoparticles embedded in an MgO support, deviations from an ideal topography during evaporation are demonstrated directly, and correlated with compositional errors in the reconstructed data. Finite element simulations of the field evaporation process confirm that protruding Au nanoparticles will evolve on the tip surface, and that evaporation field variations lead to an inaccurate assessment of the local composition, effectively lowering the spatial resolution of the final reconstructed dataset. Cross-correlating the experimental data with simulations results in a more detailed understanding of local evaporation aberrations during APT analysis of metal-oxide composites, paving the way towards a more accurate three-dimensional characterization of this technologically important class of materials.

Devaraj, Arun; Colby, Robert J.; Vurpillot, F.; Thevuthasan, Suntharampillai

2014-03-26T23:59:59.000Z

413

Depth-resolved monitoring of diffusion of hyperosmotic agents in normal and malignant human esophagus tissues using optical coherence tomography in-vitro  

SciTech Connect

Depth-resolved monitoring with differentiation and quantification of glucose diffusion in healthy and abnormal esophagus tissues has been studied in vitro. Experiments have been performed using human normal esophagus and esophageal squamous cell carcinoma (ESCC) tissues by the optical coherence tomography (OCT). The images have been continuously acquired for 120 min in the experiments, and the depth-resolved and average permeability coefficients of the 40 % glucose solution have been calculated by the OCT amplitude (OCTA) method. We demonstrate the capability of the OCT technique for depth-resolved monitoring, differentiation, and quantifying of glucose diffusion in normal esophagus and ESCC tissues. It is found that the permeability coefficients of the 40 % glucose solution are not uniform throughout the normal esophagus and ESCC tissues and increase from (3.30 {+-} 0.09) Multiplication-Sign 10{sup -6} and (1.57 {+-} 0.05) Multiplication-Sign 10{sup -5} cm s{sup -1} at the mucous membrane of normal esophagus and ESCC tissues to (1.82 {+-} 0.04) Multiplication-Sign 10{sup -5} and (3.53 {+-} 0.09) Multiplication-Sign 10{sup -5} cm s{sup -1} at the submucous layer approximately 742 {mu}m away from the epithelial surface of normal esophagus and ESCC tissues, respectively. (optical coherence tomography)

Zhao Qingliang; Guo Zhouyi; Wei Huajiang; Yang Hongqin; Xie Shusen

2011-10-31T23:59:59.000Z

414

Apparatus and method for preparing oxygen-15 labeled water H{sub 2}[{sup 15}O] in an injectable form for use in positron emission tomography  

DOE Patents (OSTI)

A handling and processing apparatus is revealed for preparing Oxygen-15 labeled water (H{sub 2}[{sup 15}O]) in injectable form for use in Positron Emission Tomography from preferably H{sub 2}[{sup 15}O] produced by irradiating a flowing gas target of nitrogen and hydrogen. The apparatus includes a collector for receiving and directing a gas containing H{sub 2}[{sup 15}O] gas and impurities, mainly ammonia (NH{sub 3}) gas into sterile water to trap the H{sub 2}[{sup 15}O] and form ammonium (NH{sub 4}{sup +}) in the sterile water. A device for displacing the sterile water containing H{sub 2}[{sup 15}O] and NH{sub 4}{sup +} through a cation resin removes NH{sub 4}{sup +} from the sterile water. A device for combining the sterile water containing H{sub 2}[{sup 15}O] with a saline solution produces an injectable solution. Preferably, the apparatus includes a device for delivering the solution to a syringe for injection into a patient. Also, disclosed is a method for preparing H{sub 2}[{sup 15}O] in injectable form for use in Positron Emission Tomography in which the method neither requires isotopic exchange reaction nor application of high temperature. 7 figs.

Ferrieri, R.A.; Schlyer, D.J.; Alexoff, D.

1996-01-09T23:59:59.000Z

415

Apparatus and method for preparing oxygen-15 labeled water H.sub.2 [.sup.15 O] in an injectable form for use in positron emission tomography  

DOE Patents (OSTI)

A handling and processing apparatus for preparing Oxygen-15 labeled water (H.sub.2 [.sup.15 O]) in injectable form for use in Positron Emission Tomography from preferably H.sub.2 [.sup.15 O] produced by irradiating a flowing gas target of nitrogen and hydrogen. The apparatus includes a collector for receiving and directing a gas containing H.sub.2 [.sup.15 O] gas and impurities, mainly ammonia (NH.sub.3) gas into sterile water to trap the H.sub.2 [.sup.15 O] and form ammonium (NH.sub.4.sup.+) in the sterile water. A device for displacing the sterile water containing H.sub.2 [.sup.15 O] and NH.sub.4.sup.+ through a cation resin removes NH.sub.4.sup.+ from the sterile water. A device for combining the sterile water containing H.sub.2 [.sup.15 O] with a saline solution produces an injectable solution. Preferably, the apparatus includes a device for delivering the solution to a syringe for injection into a patient. Also, disclosed is a method for preparing H.sub.2 [.sup.15 O] in injectable form for use in Positron Emission Tomography in which the method neither requires isotopic exchange reaction nor application of high temperature.

Ferrieri, Richard A. (Patchogue, NY); Schlyer, David J. (Bellport, NY); Alexoff, David (Westhampton, NY)

1996-01-09T23:59:59.000Z

416

Neutron wave packet tomography  

E-Print Network (OSTI)

A tomographic technique is introduced in order to determine the quantum state of the center of mass motion of neutrons. An experiment is proposed and numerically analyzed.

G. Badurek; P. Facchi; Y. Hasegawa; Z. Hradil; S. Pascazio; H. Rauch; J. Rehacek; T. Yoneda

2005-03-29T23:59:59.000Z

417

Atom Probe Tomography | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

Engineered nanocrystalline... First-principles study of defects and phase transition in UO2. The electronic properties, structure and phase transformation of UO2 have...

418

Evaluation of Treatment-Associated Inflammatory Response on Diffusion-Weighted Magnetic Resonance Imaging and 2-[18F]-Fluoro-2-Deoxy-d-Glucose-Positron Emission Tomography Imaging Biomarkers  

Science Journals Connector (OSTI)

...CS , Young H, O'Reilly SM, et al. Early evaluation...TZ , Turkington TG, Hawk TC Coleman RE. PET and brain...0 Antineoplastic Agents 0 Radiopharmaceuticals 154-93-8 Carmustine 50-02-2...Positron-Emission Tomography Radiopharmaceuticals diagnostic use Rats

Craig J. Galbán; Mahaveer S. Bhojani; Kuei C. Lee; Charles R. Meyer; Marcian E. Van Dort; Kyle K. Kuszpit; Robert A. Koeppe; Rajesh Ranga; Bradford A. Moffat; Timothy D. Johnson; Thomas L. Chenevert; Alnawaz Rehemtulla; and Brian D. Ross

2010-03-01T23:59:59.000Z

419

Thoracic target volume delineation using various maximum-intensity projection computed tomography image sets for radiotherapy treatment planning  

SciTech Connect

Purpose: Four-dimensional computed tomography (4D-CT) is commonly used to account for respiratory motion of target volumes in radiotherapy to the thorax. From the 4D-CT acquisition, a maximum-intensity projection (MIP) image set can be created and used to help define the tumor motion envelope or the internal gross tumor volume (iGTV). The purpose of this study was to quantify the differences in automatically contoured target volumes for usage in the delivery of stereotactic body radiation therapy using MIP data sets generated from one of the four methods: (1) 4D-CT phase-binned (PB) based on retrospective phase calculations, (2) 4D-CT phase-corrected phase-binned (PC-PB) based on motion extrema, (3) 4D-CT amplitude-binned (AB), and (4) cine CT built from all available images. Methods: MIP image data sets using each of the four methods were generated for a cohort of 28 patients who had prior thoracic 4D-CT scans that exhibited lung tumor motion of at least 1 cm. Each MIP image set was automatically contoured on commercial radiation treatment planning system. Margins were added to the iGTV to observe differences in the final simulated planning target volumes (PTVs). Results: For all patients, the iGTV measured on the MIP generated from the entire cine CT data set (iGTV{sub cine}) was the largest. Expressed as a percentage of iGTV{sub cine}, 4D-CT iGTV (all sorting methods) ranged from 83.8% to 99.1%, representing differences in the absolute volume ranging from 0.02 to 4.20 cm{sup 3}; the largest average and range of 4D-CT iGTV measurements was from the PC-PB data set. Expressed as a percentage of PTV{sub cine} (expansions applied to iGTV{sub cine}), the 4D-CT PTV ranged from 87.6% to 99.6%, representing differences in the absolute volume ranging from 0.08 to 7.42 cm{sup 3}. Regions of the measured respiratory waveform corresponding to a rapid change of phase or amplitude showed an increased susceptibility to the selection of identical images for adjacent bins. Duplicate image selection was most common in the AB implementation, followed by the PC-PB method. The authors also found that the image associated with the minimum amplitude measurement did not always correlate with the image that showed maximum tumor motion extent. Conclusions: The authors identified cases in which the MIP generated from a 4D-CT sorting process under-represented the iGTV by more than 10% or up to 4.2 cm{sup 3} when compared to the iGTV{sub cine}. They suggest utilization of a MIP generated from the full cine CT data set to ensure maximum inclusive tumor extent.

Zamora, David A.; Riegel, Adam C.; Sun Xiaojun; Balter, Peter; Starkschall, George; Mawlawi, Osama; Pan Tinsu [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

2010-11-15T23:59:59.000Z

420

Multispectral breast imaging using a ten-wavelength, 64x64 source/detector channels silicon photodiode-based diffuse optical tomography system  

SciTech Connect

We describe a compact diffuse optical tomography system specifically designed for breast imaging. The system consists of 64 silicon photodiode detectors, 64 excitation points, and 10 diode lasers in the near-infrared region, allowing multispectral, three-dimensional optical imaging of breast tissue. We also detail the system performance and optimization through a calibration procedure. The system is evaluated using tissue-like phantom experiments and an in vivo clinic experiment. Quantitative two-dimensional (2D) and three-dimensional (3D) images of absorption and reduced scattering coefficients are obtained from these experiments. The ten-wavelength spectra of the extracted reduced scattering coefficient enable quantitative morphological images to be reconstructed with this system. From the in vivo clinic experiment, functional images including deoxyhemoglobin, oxyhemoglobin, and water concentration are recovered and tumors are detected with correct size and position compared with the mammography.

Li Changqing; Zhao Hongzhi; Anderson, Bonnie; Jiang Huabei [Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 (United States); Department of Radiology, Oconee Memorial Hospital, Seneca, South Carolina 29672 (United States); Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 (United States)

2006-03-15T23:59:59.000Z

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421

The mechanism of DNA ejection in the Bacillus anthracis spore-binding phage 8a revealed by cryo-electron tomography  

SciTech Connect

The structure of the Bacillus anthracis spore-binding phage 8a was determined by cryo-electron tomography. The phage capsid forms a T = 16 icosahedron attached to a contractile tail via a head-tail connector protein. The tail consists of a six-start helical sheath surrounding a central tail tube, and a structurally novel baseplate at the distal end of the tail that recognizes and attaches to host cells. The parameters of the icosahedral capsid lattice and the helical tail sheath suggest protein folds for the capsid and tail-sheath proteins, respectively, and indicate evolutionary relationships to other dsDNA viruses. Analysis of 2518 intact phage particles show four distinct conformations that likely correspond to four sequential states of the DNA ejection process during infection. Comparison of the four observed conformations suggests a mechanism for DNA ejection, including the molecular basis underlying coordination of tail sheath contraction and genome release from the capsid.

Fu, Xiaofeng [Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States)] [Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States); Walter, Michael H. [Department of Biology, University of Northern Iowa, Cedar Falls, IA 50614 (United States)] [Department of Biology, University of Northern Iowa, Cedar Falls, IA 50614 (United States); Paredes, Angel [Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States)] [Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States); Morais, Marc C., E-mail: mcmorais@utmb.edu [Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555 (United States); Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555 (United States); Liu, Jun, E-mail: Jun.Liu.1@uth.tmc.edu [Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States)] [Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States)

2011-12-20T23:59:59.000Z

422

Visualisation of distribution of gold nanoparticles in liver tissues ex vivo and in vitro using the method of optical coherence tomography  

SciTech Connect

The possibility of visualising the distribution of gold nanoparticles in liver by means of the method of optical coherence tomography is studied experimentally in model samples of beef liver in vitro and rat liver ex vivo. In the experiments we used the gold nanoparticles in the form of nanocages with resonance absorption in the near-IR spectral region. In the model studies the suspension of nanoparticles was applied to the surface of the sample, which then was treated with ultrasound. In the ex vivo studies the suspension of nanoparticles was injected to the laboratory rats intravenously. The image contrast and the optical depth of detection of blood vessels and liver structure components are calculated, as well as the depth of liver optical probing before and after the injection of nanoparticles. It was shown that the administration of the nanoparticle increases significantly the imaging contrast of liver blood vessels owing to the localisation of the nanoparticles therein.

Genina, Elina A; Terentyuk, G S; Khlebtsov, B N; Bashkatov, A N; Tuchin, Valerii V

2012-06-30T23:59:59.000Z

423

Muon Muon Collider: Feasibility Study  

SciTech Connect

A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring wich has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle reactions which are open to a muon collider and the physics of such reactions - what one learns and the necessary luminosity to see interesting events - are described in detail. Most of the physics accesible to an e{sup +} - e{sup -} collider could be studied in a muon collider. In addition the production of Higgs bosons in the s-channel will allow the measurement of Higgs masses and total widths to high precision; likewise, t{bar t} and W{sup +}W{sup -} threshold studies would yield m{sub t} and m{sub w} to great accuracy. These reactions are at low center of mass energy (if the MSSM is correct) and the luminosity and {Delta}p/p of the beams required for these measurements is detailed in the Physics Chapter. On the other hand, at 2 + 2 TeV, a luminosity of L {approx} 10{sup 35} cm{sup -2}s{sup -1} is desirable for studies such as, the scattering of longitudinal W bosons or the production of heavy scalar particles. Not explored in this work, but worth noting, are the opportunities for muon-proton and muon-heavy ion collisions as well as the enormous richness of such a facility for fixed target physics provided by the intense beams of neutrinos, muons, pions, kaons, antiprotons and spallation neutrons. To see all the interesting physics described herein requires a careful study of the operation of a detector in the very large background. Three sources of background have been identified. The first is from any halo accompanying the muon beams in the collider ring. Very carefully prepared beams will have to be injected and maintained. The second is due to the fact that on average 35% of the muon energy appears in its decay electron. The energy of the electron subsequently is converted into EM showers either from the synchrotron radiation they emit in the collider magnetic field or from direct collision with the surrounding material. The decays that occur as the beams traverse the low beta insert are of particular concern for detector backgrounds. A third source of background is e{sup +} - e{sup -} pair creation from {mu}{sup +} - {mu}{sup -} interaction. Studies of

Gallardo, J.C.; Palmer, R.B.; /Brookhaven; Tollestrup, A.V.; /Fermilab; Sessler, A.M.; /LBL, Berkeley; Skrinsky, A.N.; /Novosibirsk, IYF; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. /Fermilab /Brookhaven /Wisconsin U., Madison /Tel Aviv U. /Indiana U. /UCLA /LBL, Berkeley /SLAC /Argonne /Sobolev IM, Novosibirsk /UC, Davis /Munich, Tech. U. /Virginia U. /KEK, Tsukuba /DESY /Novosibirsk, IYF /Jefferson Lab /Mississippi U. /SUNY, Stony Brook /MIT /Columbia U. /Fairfield U. /UC, Berkeley; ,

2012-04-05T23:59:59.000Z

424

Muon Collider Progress: Accelerators  

E-Print Network (OSTI)

in Fig. 7. The muons lose energy in all three dimensions viaincrease the energy loss of high-energy muons compared withthat for low-energy muons. Conceptually, there are several

Zisman, Michael S.

2012-01-01T23:59:59.000Z

425

Muon Collider Progress: Accelerators  

E-Print Network (OSTI)

A N. V. Mokhov et al. , “Muon Collider Interaction RegionR. B. Palmer et al. , “Muon Colliders,” in the 9th AdvancedB. Palmer and R. Fernow, “Muon Collider Final Cooling in 30–

Zisman, Michael S.

2012-01-01T23:59:59.000Z

426

The Muon Collider  

E-Print Network (OSTI)

11] D. Summers et al. , “Muon Acceleration to 750 GeV in theThe muon collider M. S. Zisman * Lawrence Berkeley Nationalnew type of accelerator, the muon collider. This accelerator

Zisman, Michael S.

2011-01-01T23:59:59.000Z

427

The Muon Collider  

E-Print Network (OSTI)

11] D. Summers et al. , “Muon Acceleration to 750 GeV in theThe muon collider M. S. Zisman * Lawrence Berkeley Nationalnew type of accelerator, the muon collider. This accelerator

Zisman, Michael S

2010-01-01T23:59:59.000Z

428

Kicked surface muon beams  

Science Journals Connector (OSTI)

The possibility of splitting a surface muon beam into three separate components using an ... and could be very effectively used to provide muons to time differential ?SR experiments.

J. L. Beveridge

1992-01-01T23:59:59.000Z

429

Microaspiration for high-pressure freezing: a new method for ultrastructural preservation of fragile and sparse tissues for TEM and electron tomography  

SciTech Connect

High-pressure freezing is the preferred method to prepare thick biological specimens for ultrastructural studies. However, the advantages obtained by this method often prove unattainable for samples that are difficult to handle during the freezing and substitution protocols. Delicate and sparse samples are difficult to manipulate and maintain intact throughout the sequence of freezing, infiltration, embedding, and final orientation for sectioning and subsequent TEM imaging. An established approach to surmount these difficulties is the use of cellulose microdialysis tubing to transport the sample. With an inner diameter of 200 micrometers, the tubing protects small and fragile samples within the thickness constraints of high-pressure freezing, and the tube ends can be sealed to avoid loss of sample. Importantly, the transparency of the tubing allows optical study of the specimen at different steps in the process. Here, we describe the use of a micromanipulator and microinjection apparatus to handle and position delicate specimens within the tubing. We report two biologically significant examples that benefit from this approach, 3D cultures of mammary epithelial cells and cochlear outer hair cells. We illustrate the potential for correlative light and electron microscopy as well as electron tomography.

Auer, Manfred; Triffo, W.J.; Palsdottir, H.; McDonald, K.L.; Inman, J.L.; Bissell, M.J.; Raphael, R.M.; Auer, M.; Lee, J.K.

2008-02-13T23:59:59.000Z

430

Application of x-ray tomography to optimization of new NOx/NH3 mixed potential sensors for vehicle on-board emissions control  

SciTech Connect

Mixed potential sensors for the detection of hydrocarbons, NO{sub x}, and NH{sub 3} have been previously developed at Los Alamos National Laboratory (LANL). The LANL sensors have a unique design incorporating dense ceramic-pelletlmetal-wire electrodes and porous electrolytes. The performance of current-biased sensors using an yttria-stabilized zirconia (YSZ) electrolyte and platinum and La{sub 0.8}Sr{sub 0.2}CrO{sub 3} electrodes is reported. X-ray tomography has been applied to non-destructively examine internal structures of these sensors. NO{sub x} and hydrocarbon response of the sensors under various bias conditions is reported, and very little NO{sub x} response hysteresis was observed. The application of a 0.6 {mu}A bias to these sensors shifts the response from a hydrocarbon response to a NO{sub x} response equal for both NO and NO{sub 2} species at approximately 500 {sup o}C in air.

Nelson, Mark A [Los Alamos National Laboratory; Brosha, Eric L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Garzon, Fernando H [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

431

Oxidation states study of nickel in solid oxide fuel cell anode using x-ray full-field spectroscopic nano-tomography  

Science Journals Connector (OSTI)

Identifying the chemical state and coupling with morphological information in three dimensions are of great interest in energy storage materials which typically involve reduction-oxidation cycling and structural evolution. Here we apply x-ray nano-tomography with multiple x-ray energies to study oxidation states of nickel(Ni) and nickel oxide phases in Ni-yttria-stabilized zirconia (YSZ) a typical anodematerial of solid oxide fuel cells(SOFC). We present a method to quantitatively identify the nickel-based oxides from Ni-YSZ anodecomposite and obtain chemical mapping as well as associated microstructures at nanometer scale in three dimensions. NiO particles manually placed on a Ni-YSZ compositeanode were used for validation of the method while no nickel oxides were found to be present within the electrode structure as remnants of the cell fabrication process. The application of the method can be widely applied to energy storage materials including SOFCs Li-ion batteries and supercapacitors as well as other systems for oxidation and reduction study.

Yu-chen Karen Chen-Wiegart; William M. Harris; Jeffrey J. Lombardo; Wilson K. S. Chiu; Jun Wang

2012-01-01T23:59:59.000Z

432

Oblique Soft X-Ray Tomography as a Non-Destructive Method for Morphology Diagnostics in Degradation of Proton-Exchange Membrane Fuel Cell  

Science Journals Connector (OSTI)

Abstract Diagnostics of performance degradation is important for improving the durability of proton-exchange membrane (PEM) fuel cells. X-ray computed tomography (CT) is a valuable non-destructive method to study the internal structure of PEM fuel cells. However, sample cutting is usually needed for high-resolution observations, which prevents the observer from obtaining information about morphology changes during fuel cell testing. In this study, oblique soft X-ray CT has been developed and its suitability as a non-destructive method for PEM fuel cell diagnostics without sample cutting is demonstrated. The CT images of a membrane-electrode assembly (MEA) were obtained at several stages of cell operation, including hot-pressing, load cycles, wet/dry cycles, and start-up/shutdown (SU/SD) experiments. After SU/SD operation, carbon corrosion with newly generated cracks was observed in the catalyst layer at the cathode outlet of the cell, while no corrosion was observed at the cathode inlet and center and at all anode-side positions. The size of cracks in the microporous layer, especially under the rib area, decreased after cell operation. This study validates that it is possible to observe the cause of fuel cell degradation, i.e., carbon corrosion, at a certain position of the MEA under several stages of operation, without cutting the MEA.

Phengxay Deevanhxay; Takashi Sasabe; Katsunori Minami; Shohji Tsushima; Shuichiro Hirai

2014-01-01T23:59:59.000Z

433

Investigation of water and CO2 (carbon dioxide) flooding using micro-CT (micro-computed tomography) images of Berea sandstone core using finite element simulations  

Science Journals Connector (OSTI)

The present study reports a numerical investigation of water and CO2 (carbon dioxide) flooding at the pore scale of a porous medium. We use high resolution micro-computed tomography (micro-CT) images of Berea sandstone core to obtain the pore geometry. The numerical solution used for the simulation was carried out by a finite element based software package. Level Set method is used to determine the position of the interface between two immiscible fluids when oil is displaced by water and CO2, respectively. The present formulation is validated against single-phase flow through the porous structure. It is found that, fluid flow inside the pore space takes place through preferential inlet and outlet pores. For two-phase flow, it is observed that continuous displacement of oil occurs during water flooding but CO2 is able to displace oil at certain locations in the pores. Also, the separation of flow front is observed in the case of CO2 flooding. A quantitative comparison of the results obtained in two types of flooding simulations suggests that water displaces a higher volume of oil than CO2 in the time period for which the simulations are performed.

Akshay C. Gunde; Bijoyendra Bera; Sushanta K. Mitra

2010-01-01T23:59:59.000Z

434

Ultrasound guided fluorescence molecular tomography with improved quantification by an attenuation compensated born-normalization and in vivo preclinical study of cancer  

SciTech Connect

Ultrasound imaging, having the advantages of low-cost and non-invasiveness over MRI and X-ray CT, was reported by several studies as an adequate complement to fluorescence molecular tomography with the perspective of improving localization and quantification of fluorescent molecular targets in vivo. Based on the previous work, an improved dual-modality Fluorescence-Ultrasound imaging system was developed and then validated in imaging study with preclinical tumor model. Ultrasound imaging and a profilometer were used to obtain the anatomical prior information and 3D surface, separately, to precisely extract the tissue boundary on both sides of sample in order to achieve improved fluorescence reconstruction. Furthermore, a pattern-based fluorescence reconstruction on the detection side was incorporated to enable dimensional reduction of the dataset while keeping the useful information for reconstruction. Due to its putative role in the current imaging geometry and the chosen reconstruction technique, we developed an attenuation compensated Born-normalization method to reduce the attenuation effects and cancel off experimental factors when collecting quantitative fluorescence datasets over large area. Results of both simulation and phantom study demonstrated that fluorescent targets could be recovered accurately and quantitatively using this reconstruction mechanism. Finally, in vivo experiment confirms that the imaging system associated with the proposed image reconstruction approach was able to extract both functional and anatomical information, thereby improving quantification and localization of molecular targets.

Li, Baoqiang; Berti, Romain; Abran, Maxime; Lesage, Frédéric, E-mail: frederic.lesage@polymtl.ca [Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7 (Canada) [Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7 (Canada); Montreal Heart Institute, Montreal, Quebec H1T 1C8 (Canada)

2014-05-15T23:59:59.000Z

435

Quantification of Artifacts in Scanning Electron Microscopy Tomography: Improving the Reliability of Calculated Transport Parameters in Energy Applications such as Fuel Cell and Battery Electrodes  

Science Journals Connector (OSTI)

Abstract Focused ion beam and scanning electron microscopy tomography (FIB-SEMt) is commonly used to extract reactant transport relevant parameters from nano-porous materials in energy applications, such as fuel cells or batteries. Here we present an approach to virtually model the errors in FIB-SEMt which are caused by the FIB cutting distance. The errors are evaluated in terms of connectivity, solid volume fraction (SVF), conductivity, diffusivity, as well as mean grain and pore sizes. For state-of-the-art FIB-SEMt experiments, where a hydrogen fuel cell catalyst layer with 60 nm mean grain size and 40 % SVF is sectioned with a cutting distance of 15 nm, the error in our simulation ranges up to 51 % (conductivity), whereas other parameters remain largely unaffected (Laplace diffusivity, 4 %). We further present a method, employing virtual coarsening and back interpolation, to reduce FIB cutting distance errors in all investigated parameters. Both error evaluation and correction are applicable to sphere based porous materials with relevance for the energy conversion and storage sector such as polymer electrolyte membrane fuel cell catalyst layer (PEMFC CL), battery carbon binder domain (CBD) or supercapacitor electrodes.

Matthias Klingele; Roland Zengerle; Simon Thiele

2014-01-01T23:59:59.000Z

436

Analysis of atomic distribution in as-fabricated Zircaloy-2 claddings by atom probe tomography under high-energy pulsed laser  

Science Journals Connector (OSTI)

Abstract The properties of second-phase particles (SPPs) in Zircaloy-2 claddings are key factors influencing the corrosion resistance of the alloy. The chemical compositions of Zr (Fe, Cr)2 and Zr2(Fe, Ni) \\{SPPs\\} were investigated by means of pulsed laser atom probe tomography. In order to prevent specimen fracture and to analyse wide regions of the specimen, the pulsed laser energy was increased to 2.0 nJ. This gave a high yield of average of 3 × 107 ions per specimen. The Zr (Fe, Cr)2 \\{SPPs\\} contained small amounts of Ni and Si atoms, while in Zr2(Fe, Ni) \\{SPPs\\} almost all the Si was concentrated and the ratio of Zr: (Fe + Ni + Si) was 2:1. Atomic concentrations of the Zr-matrix and the \\{SPPs\\} were identified by two approaches: the first by using all the visible peaks of the mass spectrum and the second using the representative peaks with the natural abundance of the corresponding atoms. It was found that the change in the concentration between the Zr-matrix and the \\{SPPs\\} can be estimated more accurately by the second method, although Sn concentration in the Zr2(Fe, Ni) \\{SPPs\\} is slightly overestimated.

T. Sawabe; T. Sonoda; S. Kitajima; T. Kameyama

2013-01-01T23:59:59.000Z

437

A 3D electrical resistivity tomography survey to characterise the structure of a albeluvic tonguing horizon composed of distinct elementary pedological volumes  

Science Journals Connector (OSTI)

Abstract Water and gas transfer in porous media like soils are determined by their porous network, described by their structure. In soil, the horizon is usually considered to be elementary and homogeneous functioning system in the description of gas and water functioning. However, in some cases, a horizon is heterogeneous, and its structure is defined by the 3D arrangement of Elementary Pedological Volumes (EPVs). The horizon needs to be described in three dimensions to improve the characterisation of the structure and, consequently, the prediction of its hydraulic functioning. The aim of this study was to determine the feasibility of describing the 3D structure of a heterogeneous albeluvic tonguing soil horizon composed of a juxtaposition of silty white and clayey ochre EPVs, using 3D electrical resistivity tomography (ERT). Electrical measurements were compared with geostatistical analyses from soil photographs. We demonstrated that the resistivity of the white \\{EPVs\\} was greater than that of the ochre EPVs. In addition, the general soil structure and organisation of the soil horizon could be derived from the electrical resistivity data. We proposed a method to discretise the soil electrical resistivity into a binary system that corresponded to white and ochre volumes. Finally, a 3D representation of the soil structure was created that could be used to improve soil hydraulic models.

M. Séger; R. Guérin; A. Frison; H. Bourennane; G. Richard; I. Cousin

2014-01-01T23:59:59.000Z

438

The Role of Computed Tomography in the Management of the Neck After Chemoradiotherapy in Patients With Head-and-Neck Cancer  

SciTech Connect

Purpose: The aim of this study was to describe the outcome in patients with head-and neck-squamous cell carcinoma (HNSCC) followed up without neck dissection (ND) after concomitant chemoradiotherapy (CRT) based on computed tomography (CT) response. The second objective was to establish CT characteristics that can predict which patients can safely avoid ND. Methods and Materials: Between 1998 and 2007, 369 patients with node-positive HNSCC were treated with primary CRT at our institution. After a clinical and a radiologic evaluation based on CT done 6 to 8 weeks after CRT, patients were labeled with a complete neck response (CR) or with a partial neck response (PR). Results: The median follow-up was 44 months. The number of patients presenting with N3, N2, or N1 disease were 54 (15%), 268 (72%), and 47 (13%), respectively. After CRT, 263 (71%) patients reached a CR, and 253 of them did not undergo ND. Ninety-six patients reached a PR and underwent ND. Of those, 34 (35%) had residual disease on pathologic evaluation. A regression of the diameter of {>=}80% and a residual largest diameter of 15 mm of nodes had negative pathologic predictive values of 100% and 86%, respectively. The 3-year regional control and survival rates were not different between patients with CR who had no ND and patients with PR followed by ND. Conclusion: Node-positive patients presenting a CR as determined by CT evaluation 6 to 8 weeks after CRT had a low rate of regional recurrence without ND. This study also suggests that lymph node residual size and percentage of regression on CT after CRT may be useful criteria to guide clinical decisions regarding neck surgery. Those results can help diminish the number of ND procedures with negative results and their associated surgical complications.

Clavel, Sebastien, E-mail: sebastien.clavel@umontreal.ca [Department of Radiation Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Charron, Marie-Pierre [Faculte de medicine, Universite de Montreal, Montreal, Quebec (Canada); Belair, Manon [Department of Radiology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Delouya, Guila; Fortin, Bernard; Despres, Philippe [Department of Radiation Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Soulieres, Denis [Department of Medical Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Filion, Edith [Department of Radiation Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Guertin, Louis [Department of Head and Neck Surgery, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); and others

2012-02-01T23:59:59.000Z

439

Zeeman tomography of magnetic white dwarfs IV. The complex field structure of the polars EF Eri, BL Hyi, and CP Tuc  

E-Print Network (OSTI)

The magnetic fields of the accreting white dwarfs (WDs) in magnetic cataclysmic variables (mCVs) determine the accretion geometries, the emission properties, and the secular evolution of these objects. We determine the structure of the surface magnetic fields of the WDs primaries in magnetic CVs using Zeeman tomography. Our study is based on orbital-phase resolved optical flux and circular polarization spectra of the polars EF Eri, BL Hyi, and CP Tuc obtained with FORS1 at the ESO VLT. An evolutionary algorithm is used to synthesize best fits to these spectra from an extensive database of pre-computed Zeeman spectra. The general approach has been described in previous papers of this series. The results achieved with simple geometries as centered or offset dipoles are not satisfactory. Significantly improved fits are obtained for multipole expansions that are truncated at degree l(max)=3 or 5 and include all tesseral and sectoral components with 0CP Tuc and the ranges of field strength covered are similar for the dipole and multipole models, but only the latter provide access to accreting matter at the right locations on the WD. The results suggest that the field geometries of the WDs in short-period mCVs are quite complex with strong contributions from multipoles higher than the dipole in spite of a typical age of the WDs in CVs in excess of 1 Gyr. It is feasible to derive the surface field structure of an accreting WD from phase-resolved low-state circular spectropolarimetry of sufficiently high signal-to-noise ratio. The fact that independent information is available on the strength and direction of the field in the accretion spot from high-state observations helps in unraveling the global field structure.

K. Beuermann; F. Euchner; K. Reinsch; S. Jordan; B. T. Gaensicke

2006-10-26T23:59:59.000Z

440

Modeling pure methane hydrate dissociation using a numerical simulator from a novel combination of X-ray computed tomography and macroscopic data  

SciTech Connect

The numerical simulator TOUGH+HYDRATE (T+H) was used to predict the transient pure methane hydrate (no sediment) dissociation data. X-ray computed tomography (CT) was used to visualize the methane hydrate formation and dissociation processes. A methane hydrate sample was formed from granular ice in a cylindrical vessel, and slow depressurization combined with thermal stimulation was applied to dissociate the hydrate sample. CT images showed that the water produced from the hydrate dissociation accumulated at the bottom of the vessel and increased the hydrate dissociation rate there. CT images were obtained during hydrate dissociation to confirm the radial dissociation of the hydrate sample. This radial dissociation process has implications for dissociation of hydrates in pipelines, suggesting lower dissociation times than for longitudinal dissociation. These observations were also confirmed by the numerical simulator predictions, which were in good agreement with the measured thermal data during hydrate dissociation. System pressure and sample temperature measured at the sample center followed the CH{sub 4} hydrate L{sub w}+H+V equilibrium line during hydrate dissociation. The predicted cumulative methane gas production was within 5% of the measured data. Thus, this study validated our simulation approach and assumptions, which include stationary pure methane hydrate-skeleton, equilibrium hydrate-dissociation and heat- and mass-transfer in predicting hydrate dissociation in the absence of sediments. It should be noted that the application of T+H for the pure methane hydrate system (no sediment) is outside the general applicability limits of T+H.

Gupta, A.; Moridis, G.J.; Kneafsey, T.J.; Sloan, Jr., E.D.

2009-08-15T23:59:59.000Z

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441

Sample size requirements for estimating effective dose from computed tomography using solid-state metal-oxide-semiconductor field-effect transistor dosimetry  

SciTech Connect

Purpose: Effective dose (ED) is a widely used metric for comparing ionizing radiation burden between different imaging modalities, scanners, and scan protocols. In computed tomography (CT), ED can be estimated by performing scans on an anthropomorphic phantom in which metal-oxide-semiconductor field-effect transistor (MOSFET) solid-state dosimeters have been placed to enable organ dose measurements. Here a statistical framework is established to determine the sample size (number of scans) needed for estimating ED to a desired precision and confidence, for a particular scanner and scan protocol, subject to practical limitations. Methods: The statistical scheme involves solving equations which minimize the sample size required for estimating ED to desired precision and confidence. It is subject to a constrained variation of the estimated ED and solved using the Lagrange multiplier method. The scheme incorporates measurement variation introduced both by MOSFET calibration, and by variation in MOSFET readings between repeated CT scans. Sample size requirements are illustrated on cardiac, chest, and abdomen–pelvis CT scans performed on a 320-row scanner and chest CT performed on a 16-row scanner. Results: Sample sizes for estimating ED vary considerably between scanners and protocols. Sample size increases as the required precision or confidence is higher and also as the anticipated ED is lower. For example, for a helical chest protocol, for 95% confidence and 5% precision for the ED, 30 measurements are required on the 320-row scanner and 11 on the 16-row scanner when the anticipated ED is 4 mSv; these sample sizes are 5 and 2, respectively, when the anticipated ED is 10 mSv. Conclusions: Applying the suggested scheme, it was found that even at modest sample sizes, it is feasible to estimate ED with high precision and a high degree of confidence. As CT technology develops enabling ED to be lowered, more MOSFET measurements are needed to estimate ED with the same precision and confidence.

Trattner, Sigal [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Cheng, Bin [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States)] [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States); Pieniazek, Radoslaw L. [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)] [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Douglas, Pamela S. [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States)] [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States); Einstein, Andrew J., E-mail: andrew.einstein@columbia.edu [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York and Department of Radiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York (United States)

2014-04-15T23:59:59.000Z

442

Magnetoacoustic tomography with magnetic induction for high-resolution bioimepedance imaging through vector source reconstruction under the static field of MRI magnet  

SciTech Connect

Purpose: Magnetoacoustic tomography with magnetic induction (MAT-MI) is an imaging modality to reconstruct the electrical conductivity of biological tissue based on the acoustic measurements of Lorentz force induced tissue vibration. This study presents the feasibility of the authors' new MAT-MI system and vector source imaging algorithm to perform a complete reconstruction of the conductivity distribution of real biological tissues with ultrasound spatial resolution. Methods: In the present study, using ultrasound beamformation, imaging point spread functions are designed to reconstruct the induced vector source in the object which is used to estimate the object conductivity distribution. Both numerical studies and phantom experiments are performed to demonstrate the merits of the proposed method. Also, through the numerical simulations, the full width half maximum of the imaging point spread function is calculated to estimate of the spatial resolution. The tissue phantom experiments are performed with a MAT-MI imaging system in the static field of a 9.4 T magnetic resonance imaging magnet. Results: The image reconstruction through vector beamformation in the numerical and experimental studies gives a reliable estimate of the conductivity distribution in the object with a ?1.5 mm spatial resolution corresponding to the imaging system frequency of 500 kHz ultrasound. In addition, the experiment results suggest that MAT-MI under high static magnetic field environment is able to reconstruct images of tissue-mimicking gel phantoms and real tissue samples with reliable conductivity contrast. Conclusions: The results demonstrate that MAT-MI is able to image the electrical conductivity properties of biological tissues with better than 2 mm spatial resolution at 500 kHz, and the imaging with MAT-MI under a high static magnetic field environment is able to provide improved imaging contrast for biological tissue conductivity reconstruction.

Mariappan, Leo; Hu, Gang [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 (United States)] [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 (United States); He, Bin, E-mail: binhe@umn.edu [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 and Institute of Engineering in Medicine, University of Minnesota, Minnesota 55455 (United States)] [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 and Institute of Engineering in Medicine, University of Minnesota, Minnesota 55455 (United States)

2014-02-15T23:59:59.000Z

443

Local Therapeutic Results of Computed Tomography-Guided Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma: Results of 265 Tumors in 79 Patients  

SciTech Connect

Purpose. To elucidate the local therapeutic results of computed tomography (CT)-guided transcatheter arterial chemoembolization (TACE) as initial treatment for hepatocellular carcinoma (HCC), and to verify factors which affect local therapeutic results. Methods. From 1992 to 2002, 265 tumors of 79 HCC patients were treated by 139 sessions of CT-guided TACE as initial treatment. Among these 265 tumors, 182 constituted multiple new lesions, and the remaining 83 tumors were single new lesions. Local recurrence was retrospectively ascertained on follow-up CT images obtained after TACE. Results. The overall local recurrence-free rates (LR-FRs) after a single TACE session at 6, 12, and 36 months were 67%, 49%, and 28%; those of the single new lesions were 80%, 66%, and 32%; and those of tumors with complete lipiodol accumulation were 82%, 68%, and 41%, respectively. LR-FRs of tumors of the single new lesions, and those of tumors with complete lipiodol accumulation, were significantly higher than the LR-FRs of multiple new lesions and tumors with incomplete lipiodol accumulation, respectively. For single new lesions {<=}4 cm and the tumors that were one of multiple new lesions, there were no significant differences in the LR-FRs regarding the number of TACE sessions on the basis of patient, tumor location, or tumor size. Conclusion. Local therapeutic results of single new lesions were better than those of multiple new lesions, and the local therapeutic effect of TACE was not affected by the number of treatments on the basis of patient, tumor location, or tumor size.

Hayashi, Keiji [Graduate School, Tokyo Medical and Dental University, Division of Oral Health Sciences, Department of Head and Neck Reconstruction, Section of Diagnostic Radiology and Oncology (Japan)], E-mail: kjh@hte.highway.ne.jp; Ina, Hiroyasu; Tezuka, Mikio [Nakano General Hospital, Department of Radiology (Japan); Okada, Yoichi [Tokyo Metropolitan Toshima Hospital, Department of Radiology (Japan); Irie, Tetsuya [Nakano General Hospital, Department of Internal Medicine (Japan)

2007-11-15T23:59:59.000Z

444

Noninvasive Assessment of Tumor Microenvironment Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging and {sup 18}F-Fluoromisonidazole Positron Emission Tomography Imaging in Neck Nodal Metastases  

SciTech Connect

Purpose: To assess noninvasively the tumor microenvironment of neck nodal metastases in patients with head-and-neck cancer by investigating the relationship between tumor perfusion measured using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and hypoxia measured by {sup 18}F-fluoromisonidazole ({sup 18}F-FMISO) positron emission tomography (PET). Methods and Materials: Thirteen newly diagnosed head-and-neck cancer patients with metastatic neck nodes underwent DCE-MRI and {sup 18}F-FMISO PET imaging before chemotherapy and radiotherapy. The matched regions of interests from both modalities were analyzed. To examine the correlations between DCE-MRI parameters and standard uptake value (SUV) measurements from {sup 18}F-FMISO PET, the nonparametric Spearman correlation coefficient was calculated. Furthermore, DCE-MRI parameters were compared between nodes with {sup 18}F-FMISO uptake and nodes with no {sup 18}F-FMISO uptake using Mann-Whitney U tests. Results: For the 13 patients, a total of 18 nodes were analyzed. The nodal size strongly correlated with the {sup 18}F-FMISO SUV ({rho} = 0.74, p < 0.001). There was a strong negative correlation between the median k{sub ep} (redistribution rate constant) value ({rho} = -0.58, p = 0.042) and the {sup 18}F-FMISO SUV. Hypoxic nodes (moderate to severe {sup 18}F-FMISO uptake) had significantly lower median K{sup trans} (volume transfer constant) (p = 0.049) and median k{sub ep} (p = 0.027) values than did nonhypoxic nodes (no {sup 18}F-FMISO uptake). Conclusion: This initial evaluation of the preliminary results support the hypothesis that in metastatic neck lymph nodes, hypoxic nodes are poorly perfused (i.e., have significantly lower K{sup trans} and k{sub ep} values) compared with nonhypoxic nodes.

Jansen, Jacobus [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Schoeder, Heiko [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Lee, Nancy Y. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Wang Ya [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2010-08-01T23:59:59.000Z

445

Assessing Respiration-Induced Tumor Motion and Internal Target Volume Using Four-Dimensional Computed Tomography for Radiotherapy of Lung Cancer  

SciTech Connect

Purpose: To assess three-dimensional tumor motion caused by respiration and internal target volume (ITV) for radiotherapy of lung cancer. Methods and Materials: Respiration-induced tumor motion was analyzed for 166 tumors from 152 lung cancer patients, 57.2% of whom had Stage III or IV non-small-cell lung cancer. All patients underwent four-dimensional computed tomography (4DCT) during normal breathing before treatment. The expiratory phase of 4DCT images was used as the reference set to delineate gross tumor volume (GTV). Gross tumor volumes on other respiratory phases and resulting ITVs were determined using rigid-body registration of 4DCT images. The association of GTV motion with various clinical and anatomic factors was analyzed statistically. Results: The proportions of tumors that moved >0.5 cm along the superior-inferior (SI), lateral, and anterior-posterior (AP) axes during normal breathing were 39.2%, 1.8%, and 5.4%, respectively. For 95% of the tumors, the magnitude of motion was less than 1.34 cm, 0.40 cm, and 0.59 cm along the SI, lateral, and AP directions. The principal component of tumor motion was in the SI direction, with only 10.8% of tumors moving >1.0 cm. The tumor motion was found to be associated with diaphragm motion, the SI tumor location in the lung, size of the GTV, and disease T stage. Conclusions: Lung tumor motion is primarily driven by diaphragm motion. The motion of locally advanced lung tumors is unlikely to exceed 1.0 cm during quiet normal breathing except for small lesions located in the lower half of the lung.

Liu, H. Helen [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)]. E-mail: hliu@mdanderson.org; Balter, Peter [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Tutt, Teresa [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Choi, Bum [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Zhang, Joy [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Wang, Catherine [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Chi, Melinda [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Luo Dershan [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Pan Tinsu [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Hunjan, Sandeep [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Starkschall, George [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Rosen, Isaac [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Prado, Karl [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Liao Zhongxing; Chang, Joe; Komaki, Ritsuko; Cox, James D. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Mohan, Radhe; Dong Lei [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

2007-06-01T23:59:59.000Z

446

Accuracy and Efficiency of Determining Urinary Calculi Composition Using Dual-energy Computed Tomography Compared With Hounsfield Unit Measurements for Practicing Physicians  

Science Journals Connector (OSTI)

Objective To compare speed and accuracy for determining urinary calculi composition between dual-energy computed tomography (DECT) and Hounsfield unit (HU) measurements of calculi by a set of reviewers at varying levels of training and practice. Materials and Methods Sixteen patients with known stone composition were randomly selected. Fourteen reviewers of varying levels of practice interpreted DECT and HU images from the selected patients to predict stone composition in 2 sessions (day 1: tutorial or flow sheet available for image interpretation and day 2: tutorial or flow sheet not available). Reviewers recorded HU values, stone color, and predicted stone composition as they were timed. Accuracy of image interpretation, determination of calculi composition, and interpretation time were compared. Results DECT accuracy: image interpretation 100% (day 1) and 94% (day 2); predicted stone composition: 100% (day 1) and 73% (day 2). Mean interpretation time was the same for both days, 21 seconds per study (range, 11-40 seconds). HU accuracy: image interpretation 97% (day 1) and 91% (day 2); predicted stone composition was 45% accurate on both days. Mean interpretation time was 53 seconds per study (range, 28-79 seconds) and 41 seconds per study (range, 19-71 seconds) on days 1 and 2, respectively. Overall accuracy of determination of stone composition and interpretation time for DECT were essentially double those of the HU images (87% vs 45% and 21 vs 47 seconds, respectively). Reviewer's experience level did not affect accuracy or speed. Conclusion DECT is easier to learn, faster to interpret, and more accurate than HU in determining urinary calculi composition for physicians at various levels of training and practice.

Maria A. Jepperson; El-Sayed H. Ibrahim; Abby Taylor; Joseph G. Cernigliaro; William E. Haley; David D. Thiel

2014-01-01T23:59:59.000Z

447

Assessment of Gross Tumor Volume Regression and Motion Changes During Radiotherapy for Non-Small-Cell Lung Cancer as Measured by Four-Dimensional Computed Tomography  

SciTech Connect

Purpose: To investigate the magnitudes of the changes in mobility and volume of locally advanced non-small-cell lung cancer (NSCLC) tumors during radiotherapy, using four-dimensional computed tomography (4DCT). Methods and Materials: Five to ten 4DCT data sets were acquired weekly for each of 8 patients throughout treatment. Gross tumor volumes (GTVs) were outlined on each data set. Volumes and coordinates of the GTV centroids were calculated at the 0 (end-inspiration) and 50% (end-expiration) respiration phases. Trends in magnitudes of intrafraction and interfraction positional variations were assessed for the GTV and internal target volume (ITV) during treatment. Results: Tumor volume reduction ranged from 20% to 71% (end-inspiration) and from 15% to 70% (end-expiration). Increased tumor mobility was observed in the superior-inferior and anterior-posterior directions. However, no trends in tumor motion were observed. Motion along the superior-inferior direction was significantly greater (p < 0.001), with mean {+-} SD values of 0.86 {+-} 0.19 cm, as compared with 0.39 {+-} 0.08 cm and 0.19 {+-} 0.05 cm in the anterior-posterior and right-left directions, respectively. A marginally significant (p = 0.049) increase in total GTV positional variation was observed with increasing treatment weeks, and similar results were seen for the interfractional ITV mobility. Conclusions: Because of changes in tumor size and mobility, an explicit initial determination of the ITV may not be sufficient, especially where small setup margins are used. Repeat 4DCT scans might be warranted for highly mobile tumors to reduce the potential for missing the tumor.

Britton, Keith R. [Radiation Oncology Division, Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States)]. E-mail: kbritton@mdanderson.org; Starkschall, George [Radiation Oncology Division, Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Tucker, Susan L. [Department of Biostatistics and Applied Mathematics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Pan Tinsu [Department of Imaging Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Nelson, Christopher [Radiation Oncology Division, Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Chang, Joe Y. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Cox, James D. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Mohan, Radhe [Radiation Oncology Division, Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston TX (United States); Komaki, Ritsuko [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston TX (United States)

2007-07-15T23:59:59.000Z

448

Contribution of atom-probe tomography to a better understanding of glass alteration mechanisms: application to a nuclear glass specimen altered 25 years in a granitic environment  

SciTech Connect

We report and discuss results of atom probe tomography (APT) and energy-filtered transmission electron microscopy (EFTEM) applied to a borosilicate glass sample of nuclear interest altered for nearly 26 years at 90°C in a confined granitic medium in order to better understand the rate-limiting mechanisms under conditions representative of a deep geological repository for vitrified radioactive waste. The APT technique allows the 3D reconstruction of the elemental distribution at the reactive interphase with sub-nanometer precision. Profiles of the B distribution at pristine glass/hydrated glass interface obtained by different techniques are compared to show the challenge of accurate measurements of diffusion profiles at this buried interface on the nanometer length scale. Our results show that 1) Alkali from the glass and hydrogen from the solution exhibit anti-correlated 15 ± 3 nm wide gradients located between the pristine glass and the hydrated glass layer, 2) boron exhibits an unexpectedly sharp profile located just at the outside of the alkali/H interdiffusion layer; this sharp profile is more consistent with a dissolution front than a diffusion-controlled release of boron. The resulting apparent diffusion coefficients derived from the Li and H profiles are DLi = 1.5 × 10-22 m2.s-1 and DH = 6.8 × 10-23 m2.s-1. These values are around two orders of magnitude lower than those observed at the very beginning of the alteration process, which suggests that interdiffusion is slowed at high reaction progress by local conditions that could be related to the porous structure of the interphase. As a result, the accessibility of water to the pristine glass could be the rate-limiting step in these conditions. More generally, these findings strongly support the importance of interdiffusion coupled with hydrolysis reactions of the silicate network on the long-term dissolution rate, contrary to what has been suggested by recent interfacial dissolution-precipitation models for silicate minerals.

Gin, Stephane [CEA Marcoule DTCD SECM LCLT, Bagnols-sur-Ceze (France); Ryan, Joseph V. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Schreiber, Daniel K. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Neeway, James J. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Cabie, M. [Aix-Marseille Universite, CP2M, Marseille (France)

2013-06-26T23:59:59.000Z

449

The Effect of a Contrast Agent on Proton Beam Range in Radiotherapy Planning Using Computed Tomography for Patients With Locoregionally Advanced Lung Cancer  

SciTech Connect

Purpose: We evaluated the effect of a contrast agent (CA) on proton beam range in a treatment planning system (TPS) for patients with locoregionally advanced lung cancer. Methods and Materials: Two sets of computed tomography (CT) images (with and without CA) were obtained from 20 patients with lung cancer. Because the increase in Hounsfield unit ( Increment HU) value of the heart and great vessels due to the effect of CA is most prominent among thoracic structures, to evaluate the effect of CA on proton beam range in the TPS, we compared the calculated distal ranges in the plan with CA-enhanced CT with those with corrected CT, in which the HU values of the heart and great vessels in the CA-enhanced CT were replaced by average HU values obtained from the unenhanced CT. Results: The mean Increment HU value and the longest length of the heart and great vessels within the proton beam path in the field that passed through these structures were 189 {+-} 29 HU (range, 110-250 HU) and 7.1 {+-} 1.1 cm (range, 2.6-11.2 cm), respectively. The mean distal range error in the TPS because of the presence of CA was 1.0 {+-} 0.7 cm (range, 0.2-2.6 cm). Conclusion: If CA-enhanced CT images are used for radiotherapy planning using a proton beam for the treatment of lung cancer, our results suggest that the HU values of the heart and great vessels should be replaced by the average HU values of soft tissue to avoid discrepancies between planned and delivered doses.

Hwang, Ui-Jung; Shin, Dong Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Kim, Tae Hyun, E-mail: k2onco@naver.com [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Moon, Sung Ho; Lim, Young Kyung; Jeong, Hojin; Rah, Jeong-Eun; Kim, Sang Soo; Kim, Joo-Young; Kim, Dae Yong; Park, Sung Yong; Cho, Kwan Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of)

2011-11-15T23:59:59.000Z

450

Atmospheric Muons and Neutrinos  

Science Journals Connector (OSTI)

......parameters to reproduce the observed muon energy spectrum in a certain zenithal...If we restrict ourselves to the muons of energy greater than, say, 5 GeV, we...parameters to reproduce the observed muon energy spectrum in a certain zenithal......

Masatoshi Koshiba

1969-03-01T23:59:59.000Z

451

Muon Front End for a Neutrino Factory and Muon Collider  

E-Print Network (OSTI)

Muon Front End for a Neutrino Factory and Muon Collider Chris Rogers, ASTeC, Rutherford Appleton Laboratory 15th January 2013 #12;High Energy Muon Facilities Growing interest in large, high energy muon facilities Neutrino Factory -> neutrino oscillations and Muon Collider -> energy frontier or Higgs factory

McDonald, Kirk

452

AN INTENSE LOW ENERGY MUON SOURCE FOR THE MUON COLLIDER  

E-Print Network (OSTI)

AN INTENSE LOW ENERGY MUON SOURCE FOR THE MUON COLLIDER D. Taqqu Paul Scherrer Institut, Villigen, CH Abstract A scheme for obtaining an intense source of low energy muons is described. It is based of the decay muons an intense intermediate energy muon beam is obtained. For the specific case of negative

McDonald, Kirk

453

Determination of time-course change rate for arterial xenon using the time course of tissue xenon concentration in xenon-enhanced computed tomography  

SciTech Connect

In calculating tissue blood flow (TBF) according to the Fick principle, time-course information on arterial tracer concentration is indispensable and has a considerable influence on the accuracy of calculated TBF. In TBF measurement by xenon-enhanced computed tomography (Xe-CT), nonradioactive xenon gas is administered by inhalation as a tracer, and end-tidal xenon is used as a substitute for arterial xenon. There has been the assumption that the time-course change rate for end-tidal xenon concentration (Ke) and that for arterial xenon concentration (Ka) are substantially equal. Respiratory gas sampling is noninvasive to the patient and Ke can be easily measured by exponential curve fitting to end-tidal xenon concentrations. However, it is pointed out that there would be a large difference between Ke and Ka in many cases. The purpose of this work was to develop a method of determining the Ka value using the time course of tissue xenon concentration in Xe-CT. The authors incorporated Ka into the Kety autoradiographic equation as a parameter to be solved, and developed a method of least-squares to obtain the solution for Ka from the time-course changes in xenon concentration in the tissue. The authors applied this method of least-squares to the data from Xe-CT abdominal studies performed on 17 patients; the solution for Ka was found pixel by pixel in the spleen, and its Ka map was created for each patient. On the one hand, the authors obtained the average value of the Ka map of the spleen as the calculated Ka (Ka{sub calc}) for each patient. On the other hand, the authors measured Ka (Ka{sub meas}) using the time-course changes in CT enhancement in the abdominal aorta for each patient. There was a good correlation between Ka{sub calc} and Ka{sub meas} (r=0.966, P<0.0001), and these two Ka values were close to each other (Ka{sub calc}=0.935xKa{sub meas}+0.089). This demonstrates that Ka{sub calc} would be close to the true Ka value. Accuracy of TBF by Xe-CT can be improved with use of the average value of the Ka map of an organ like the spleen that has a single blood supply (only arterial inflow)

Sase, Shigeru; Takahashi, Hideaki; Ikeda, Hiroki; Kobayashi, Minoru; Matsumoto, Nobuyuki; Suzuki, Michihiro [Anzai Medical Co., Ltd., 3-9-15 Nishi-Shinagawa, Shinagawa-ku, Tokyo 141-0033 (Japan); Department of Internal Medicine, Division of Gastroenterology and Hepatology, School of Medicine, St. Marianna University, 2-16-1 Miyamae-ku, Sugao, Kawasaki 216-5811 (Japan)

2008-06-15T23:59:59.000Z

454

A Comparison of Amplitude-Based and Phase-Based Positron Emission Tomography Gating Algorithms for Segmentation of Internal Target Volumes of Tumors Subject to Respiratory Motion  

SciTech Connect

Purpose: To quantitatively compare the accuracy of tumor volume segmentation in amplitude-based and phase-based respiratory gating algorithms in respiratory-correlated positron emission tomography (PET). Methods and Materials: List-mode fluorodeoxyglucose-PET data was acquired for 10 patients with a total of 12 fluorodeoxyglucose-avid tumors and 9 lymph nodes. Additionally, a phantom experiment was performed in which 4 plastic butyrate spheres with inner diameters ranging from 1 to 4 cm were imaged as they underwent 1-dimensional motion based on 2 measured patient breathing trajectories. PET list-mode data were gated into 8 bins using 2 amplitude-based (equal amplitude bins [A1] and equal counts per bin [A2]) and 2 temporal phase-based gating algorithms. Gated images were segmented using a commercially available gradient-based technique and a fixed 40% threshold of maximum uptake. Internal target volumes (ITVs) were generated by taking the union of all 8 contours per gated image. Segmented phantom ITVs were compared with their respective ground-truth ITVs, defined as the volume subtended by the tumor model positions covering 99% of breathing amplitude. Superior-inferior distances between sphere centroids in the end-inhale and end-exhale phases were also calculated. Results: Tumor ITVs from amplitude-based methods were significantly larger than those from temporal-based techniques (P=.002). For lymph nodes, A2 resulted in ITVs that were significantly larger than either of the temporal-based techniques (P<.0323). A1 produced the largest and most accurate ITVs for spheres with diameters of ?2 cm (P=.002). No significant difference was shown between algorithms in the 1-cm sphere data set. For phantom spheres, amplitude-based methods recovered an average of 9.5% more motion displacement than temporal-based methods under regular breathing conditions and an average of 45.7% more in the presence of baseline drift (P<.001). Conclusions: Target volumes in images generated from amplitude-based gating are larger and more accurate, at levels that are potentially clinically significant, compared with those from temporal phase-based gating.

Jani, Shyam S., E-mail: sjani@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, California (United States); Robinson, Clifford G. [Department of Radiation Oncology, Siteman Cancer Center, Washington University in St Louis, St Louis, Missouri (United States); Dahlbom, Magnus [Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, California (United States); White, Benjamin M.; Thomas, David H.; Gaudio, Sergio; Low, Daniel A.; Lamb, James M. [Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, California (United States)

2013-11-01T23:59:59.000Z

455

Development and Implementation of 3-D, High Speed Capacitance Tomography for Imaging Large-Scale, Cold-Flow Circulating Fluidized Bed  

SciTech Connect

A detailed understanding of multiphase flow behavior inside a Circulating Fluidized Bed (CFB) requires a 3-D technique capable of visualizing the flow field in real-time. Electrical Capacitance Volume Tomography (ECVT) is a newly developed technique that can provide such measurements. The attractiveness of the technique is in its low profile sensors, fast imaging speed and scalability to different section sizes, low operating cost, and safety. Moreover, the flexibility of ECVT sensors enable them to be designed around virtually any geometry, rendering them suitable to be used for measurement of solid flows in exit regions of the CFB. Tech4Imaging LLC has worked under contract with the U.S. Department of Energyâ??s National Energy Technology Laboratory (DOE NETL) to develop an ECVT system for cold flow visualization and install it on a 12 inch ID circulating fluidized bed. The objective of this project was to help advance multi-phase flow science through implementation of an ECVT system on a cold flow model at DOE NETL. This project has responded to multi-phase community and industry needs of developing a tool that can be used to develop flow models, validate computational fluid dynamics simulations, provide detailed real-time feedback of process variables, and provide a comprehensive understating of multi-phase flow behavior. In this project, a complete ECVT system was successfully developed after considering different potential electronics and sensor designs. The system was tested at various flow conditions and with different materials, yielding real-time images of flow interaction in a gas-solid flow system. The system was installed on a 12 inch ID CFB of the US Department of Energy, Morgantown Labs. Technical and economic assessment of Scale-up and Commercialization of ECVT was also conducted. Experiments conducted with larger sensors in conditions similar to industrial settings are very promising. ECVT has also the potential to be developed for imaging multi-phase flow systems in high temperature and high pressure conditions, typical in many industrial applications.

Qussai Marashdeh

2012-09-30T23:59:59.000Z

456

MUON SCATTERING INTO 1-5 MUON FINAL STATES  

E-Print Network (OSTI)

MUON SCATTERING INTO1 - 5 MUON FINAL STATES Physics Depar~ment and Lawrenceof 209-GeV and 90-GeV muons within a magnetized~steel

Clark, A.R.

2010-01-01T23:59:59.000Z

457

Ultrasound-modulated optical tomography  

E-Print Network (OSTI)

a0a2a1a4a3a6a5a2a7a2a8a10a9a11a0a13a12a13a14a16a15a18a17a19a9a11a14a20a0a13a1a21a7a22a3a24a23a25a14 a9a11a26a27a3a6a28a30a29a24a7a13a1a31a3a6a9a11a17a19a9a11a32a11a5a2a7a2a26a27a33a27a34 a7a35a14a37a36a39a38a40a38a18a41a43a42a45a44a47a46a48a44a47a36... a39a49a51a50 a52a54a53 a33a13a7a13a23a56a55a57a9a11a12a58a12a2a7a13a17 a8a10a59 a52a10a60 a36a61a44a62a44a47a41a43a63a64a44a47a49a20a44a54a65a10a41a66a9a11a67a69a68a43a41a11a49a51a70a71a32a66a42a62a46a51a63a10a59a10a46a72a44a54a41a66a8a73a44a54a59a10...

Nam, Haewon

2004-09-30T23:59:59.000Z

458

Mathematical Problems of Thermoacoustic Tomography  

E-Print Network (OSTI)

formulas to reconstruct the initial perturbation from the observed data. The second problem is the range description. We present the range description of the spherical mean Radon transform, which is an important transform in TAT. The next problem...

Nguyen, Linh V.

2010-10-12T23:59:59.000Z